toolchain: banner purge + WHY-only comment sweep (rule 8)

selfhost/, cmd/, internal/ join the tree-wide sweep: every section
banner dies (91 selfhost + the cmd C-style dividers -> 0); narration
and stale contracts deleted (pre-#22 bundler notes, retired
single-PT_LOAD and no-archive claims, superseded ABI tables); every
ref/harec/qbe cite, task cite, encoding/ELF contract, and rule-10
twin pointer kept; lost lifetime/rationale lines restored where the
sweep over-cut (elf_globals ownership, kwtab linear-scan). Comment-
only proven: all five wwstage tool binaries byte-identical across
the sweep; test-commit, test-byteid (161+1399, 0 pinned-divergent),
and test-bootstrap (fixed point + 991-995 byte-id) all exit 0.
The read-through banked 66 latent-bug leads (checkpoint).

cmd/w6c/6.out.h

@@ -114,7 +114,7 @@ enum {
 	A_LAST
 };
 
-const char *anames(int);	/* opcode -> mnemonic */
-const char *rnames(int);	/* register -> name */
+const char *anames(int);
+const char *rnames(int);
 
 #endif

cmd/w6c/cgen.c

@@ -1366,9 +1366,9 @@ let_emit_size(Type *t)
 	}
 }
 
-/* Is the unwrapped type a str? Used by the load/store paths so the
- * (AX, BX) pair convention is preserved for str globals, mirroring
- * what we already do for str locals. */
+/* Used by the load/store paths so the (AX, BX) pair convention is
+ * preserved for str globals, mirroring what we already do for str
+ * locals. */
 static int
 let_isstr(Type *t)
 {
@@ -1377,8 +1377,8 @@ let_isstr(Type *t)
 	return u && u->kind == TY_STR;
 }
 
-/* Is the unwrapped type a slice? Slice globals flow as the (AX, BX,
- * CX) triple — same as the local ABI. */
+/* Slice globals flow as the (AX, BX, CX) triple — same as the local
+ * ABI. */
 static int
 let_isslice(Type *t)
 {
@@ -1387,9 +1387,9 @@ let_isslice(Type *t)
 	return u && u->kind == TY_SLICE;
 }
 
-/* Is the unwrapped type a struct? Struct globals only support field
- * access (read + plain `=` write for scalar fields). Whole-struct
- * by-value flow through expressions isn't wired. */
+/* Struct globals only support field access (read + plain `=` write
+ * for scalar fields). Whole-struct by-value flow through expressions
+ * isn't wired. */
 static int
 let_isstruct(Type *t)
 {
@@ -1398,9 +1398,8 @@ let_isstruct(Type *t)
 	return u && u->kind == TY_STRUCT;
 }
 
-/* Is the unwrapped type a fixed-length array? Array globals are
- * zero-init DATAW slots; cgindex addresses them as LEAQ name(SB)
- * and lets the element load/store run as usual. */
+/* Array globals are zero-init DATAW slots; cgindex addresses them as
+ * LEAQ name(SB) and lets the element load/store run as usual. */
 static int
 let_isarray(Type *t)
 {
@@ -1409,9 +1408,9 @@ let_isarray(Type *t)
 	return u && u->kind == TY_ARRAY;
 }
 
-/* Is the unwrapped type a float (f32 or f64)? Float globals flow
- * through X0 — load/store goes LEAQ name(SB),CX → MOVSS/MOVSD via the
- * indirect, since the asm has no D_EXTERN form for SSE moves yet. */
+/* Float globals flow through X0 — load/store goes LEAQ name(SB),CX →
+ * MOVSS/MOVSD via the indirect, since the asm has no D_EXTERN form
+ * for SSE moves yet. */
 static int
 let_isfloat(Type *t)
 {
@@ -1722,7 +1721,6 @@ let_var_type(const char *name)
 	return NULL;
 }
 
-/* Glue `<module>.<ident>` into a fresh arena buffer. */
 static const char *
 mod_join(Cg *c, const char *mod, const char *ident)
 {
@@ -1944,9 +1942,6 @@ cgslicehdr(Cg *c, int base)
 	else if (base == D_AX) ins2(c, A_MOVQ, amem(base, 0), areg(D_AX));
 }
 
-/* ------------------------------------------------------------------ */
-/* per-fn local table: name → stack offset (positive = below FP) */
-
 typedef struct Local Local;
 struct Local {
 	const char *name;
@@ -2074,8 +2069,7 @@ cg_base_cap(Cg *c, Node *base, Type *bu, Local *locals, int dst)
 	return 0;
 }
 
-/* ------------------------------------------------------------------ */
-/* expressions: result lands in AX. Returns 1 on success. */
+/* expressions: result lands in AX. */
 
 static void cgexpr(Cg*, Node*, Local*);
 static void cgstmt(Cg*, Node*, Local**, int*);
@@ -4678,7 +4672,6 @@ cgexpr(Cg *c, Node *n, Local *locals)
 					}
 				}
 				if (amped) break;
-				/* Fall through to silent-drop fallback below. */
 			}
 			if (opnd && opnd->kind == N_INDEX) {
 				/* &base[i] = base + i*esz, no dereference.
@@ -5436,7 +5429,6 @@ cgexpr(Cg *c, Node *n, Local *locals)
 			}
 		after_dot_assign:
 			if (u && u->kind == TY_STRUCT) {
-				/* find field metadata */
 				Tfield *f = NULL;
 				for (Tfield *fl = u->fields; fl; fl = fl->next)
 					if (strcmp(fl->name, n->lhs->str) == 0)
@@ -5725,7 +5717,6 @@ cgexpr(Cg *c, Node *n, Local *locals)
 					}
 					break;
 				}
-				/* now store AX into target */
 				if (via_ptr) {
 					if (boff == 0 && let_islet(base->str)) {
 						/* #47 (inverse): a GLOBAL *struct
@@ -15147,7 +15138,6 @@ cgstmt(Cg *c, Node *n, Local **locals, int *frame)
 			baseoff = localoff(c, locals, bname, 8, frame);
 		}
 
-		/* allocate per-name slots */
 		struct { int off, sz, foff; Type *ftype; } binds[8] = {0};
 		int nbinds = 0;
 		if (destruct) {
@@ -15733,7 +15723,6 @@ cgfn(Cg *c, FILE *out, Node *fn)
 {
 	if (fn->body == NULL) return;	/* extern decl, no body */
 
-	/* fresh per-fn state */
 	c->head = c->tail = NULL;
 	c->fnname = fn->str;
 	c->cur_mod = (fn->module && fn->module[0]) ? fn->module : NULL;
@@ -15788,7 +15777,6 @@ cgfn(Cg *c, FILE *out, Node *fn)
 	text->from.offset = 0;	/* framesize patched below */
 	emit(c, text);
 
-	/* prologue */
 	ins1(c, A_PUSHQ, areg(D_BP));
 	ins2(c, A_MOVQ, areg(D_SP), areg(D_BP));
 	Prog *subsp = newprog(c, A_SUBQ);

cmd/w6c/gc.h

@@ -1,7 +1,4 @@
-/*
- * gc.h — w6c-private header: Prog/Adr structs, scratch register set,
- * stack-frame state. Plan 9 cmd/6c/gc.h shape, trimmed.
- */
+/* Plan 9 cmd/6c/gc.h shape, trimmed. */
 #ifndef SIX_GC_H
 #define SIX_GC_H
 
@@ -73,9 +70,7 @@ void	emit(Cg*, Prog*);
 /* txt.c */
 void	txt_emit(FILE*, Prog *head);
 
-/* wwi.c — `.wwi` export-data producer (w6c -I). M2 dead-code: writes a
- * re-parseable ww-prototype rendering of the package's exported surface.
- * Returns non-zero if check_exported_type rejects a dangling export. */
+/* wwi.c — non-zero return: check_exported_type rejected a dangling export. */
 int	wwi_emit(Checker *c, FILE *of, Node *file);
 
 /* swt.c, peep.c, reg.c — placeholders for now */

cmd/w6c/main.c

@@ -1,9 +1,3 @@
-/*
- * w6c — amd64 compiler driver. Reads a .ww source file, runs the
- * libwcc frontend (lex → parse → check), then walks the typed AST
- * via cgen.c and writes Plan 9-flavoured amd64 asm to stdout (or
- * the file given by -o).
- */
 #include "gc.h"
 #include <stdio.h>
 #include <stdlib.h>

cmd/w6c/peep.c

@@ -1,7 +1,7 @@
 /*
- * peep.c — peephole pass. Currently a no-op; reserved for the kind of
- * cleanup Plan 9 6c does (folding adjacent moves, removing redundant
- * compares). Wire in `peephole(c)` from cgen.c after the main walk.
+ * Currently a no-op; reserved for the kind of cleanup Plan 9 6c does
+ * (folding adjacent moves, removing redundant compares). Wire in
+ * `peephole(c)` from cgen.c after the main walk.
  */
 #include "gc.h"
 

cmd/w6c/reg.c

@@ -1,8 +1,8 @@
 /*
- * reg.c — register allocator. The current cgen pins everything to AX
- * with BX as a scratch top-of-stack — no real allocation. This file
- * is the seam where a linear-scan or graph-colouring pass would land
- * later; today it's empty.
+ * The current cgen pins everything to AX with BX as a scratch
+ * top-of-stack — no real allocation. This file is the seam where a
+ * linear-scan or graph-colouring pass would land later; today it's
+ * empty.
  */
 #include "gc.h"
 

cmd/w6c/swt.c

@@ -1,7 +1,7 @@
 /*
- * swt.c — switch-statement lowering. Stub for now: cgen falls
- * through to a no-op for N_SWITCH. When we add a real lowering, it
- * will live here, mirroring Plan 9 6c's pswt.c.
+ * Stub for now: cgen falls through to a no-op for N_SWITCH. When we
+ * add a real lowering, it will live here, mirroring Plan 9 6c's
+ * pswt.c.
  */
 #include "gc.h"
 

cmd/w6c/txt.c

@@ -1,6 +1,4 @@
 /*
- * txt.c — print a Prog list as Plan 9-flavoured amd64 asm text.
- *
  * Format we emit (and that w6a expects):
  *   TEXT name<framesize>
  *       MOVQ $1, AX

cmd/w6c/wwi.c

@@ -35,11 +35,11 @@ wwi_primary(Node *n)
 	return n && n->imported == 0;
 }
 
-/* --- check_exported_type (drew) ------------------------------------- *
- * Resolve an N_TNAME to its type sym WITHOUT the side effects of
- * resolve_typename (no on-demand resolve, no double "unknown type"
- * error). A primitive/keyword resolves to no SK_TYPE → leaf. By the
- * time the producer runs, check_file has finished and c->cur == c->top.
+/* check_exported_type (drew): resolve an N_TNAME to its type sym WITHOUT
+ * the side effects of resolve_typename (no on-demand resolve, no double
+ * "unknown type" error). A primitive/keyword resolves to no SK_TYPE →
+ * leaf. By the time the producer runs, check_file has finished and
+ * c->cur == c->top.
  */
 static Sym *
 wwi_typesym(Checker *c, const char *nm)
@@ -141,7 +141,7 @@ wwi_check_decl(Checker *c, Node *d)
 	return bad;
 }
 
-/* --- type-expr + const-expr unparser (rob §2.2/§2.4) ---------------- */
+/* type-expr unparse per rob §2.2; const-expr per rob §2.4. */
 
 static void wwi_expr(FILE *of, Node *e);
 static void wwi_type(FILE *of, Node *t);
@@ -447,7 +447,7 @@ wwi_decl(FILE *of, Node *d)
 	}
 }
 
-/* --- deterministic ordering (rob §3) -------------------------------- */
+/* deterministic ordering per rob §3. */
 
 struct declent { Node *d; int idx; };
 struct useent  { const char *path; int idx; };