test: retarget Pattern-B gates to sep .sepwork layout; 915 off private global (M4 E3, #93)

The driver flip moves build artifacts from next-to-source <stem>.s to a
.sepwork/ scratch dir. 29 Pattern-B gates now build `ww build --sep -o <stem>`
and read <stem>.sepwork/__root.s (multi-package gates concat all
<stem>.sepwork/*.s, since cross-package labels live in per-package .s).
All intermediates redirect to /tmp (WW_PKGCACHE + -o), so the corpus runs
parallel-safe with no source-tree pollution. Tests pass now (--sep is live)
and survive the flip.

915 additionally retargeted off strconv's PRIVATE left_shift_table (a let,
not export) — which separate compilation correctly hides — onto a test-local
package that exports its own probe table (#96). The combined path only linked
it via a single-unit private leak; encapsulation is now honored under sep.

Test-only; all 5 *_ww binaries HOLD. 989_m1mangle_run deferred (blocked by
#99, imported-package fn main mangling under sep).

test/wcc/992_w6l_ww.c

@@ -56,40 +56,57 @@ slurp(const char *path, char **outbuf, size_t *outlen)
 	return 0;
 }
 
-/* link `inputs` (space-separated, the caller's responsibility to quote)
- * with both linkers, compare bytes. */
+/* #93 sep layout: the flip stops emitting a monolithic <tool>/main.o;
+ * the linkable unit is now the per-package .o + reverse-topo .a set the
+ * sep driver assembles (a raw `w6l <root>.o *.a libwwrt.a` from the test
+ * side fails — `undefined reference` — because it can't reproduce the
+ * driver's topo order). So isolate the LINKER by driving the sep build's
+ * own link step twice over identical .o inputs (a shared pkgcache makes
+ * the second build's package objects a cache hit → only the final link
+ * re-runs): once with the default C w6l, once with WW_W6L=w6l_ww. Diff
+ * the two real tool binaries. Exercises the full archive two-pass loader
+ * + reverse-topo .a resolution — a stronger link than the old single
+ * main.o. Flip-invariant: --sep is live on trunk, default post-flip. */
 static int
-diff_one(const char *bin, const char *label, const char *inputs)
+build_and_diff(const char *bin, const char *cwd, const char *tool,
+    const char *cache)
 {
-	char co[64], wo[64], cmd[4096];
-	snprintf(co, sizeof co, "/tmp/wwl_%d_c", getpid());
-	snprintf(wo, sizeof wo, "/tmp/wwl_%d_w", getpid());
+	char cstem[256], wstem[256], cmd[4096];
+	snprintf(cstem, sizeof cstem, "/tmp/wwl_%d_c", getpid());
+	snprintf(wstem, sizeof wstem, "/tmp/wwl_%d_w", getpid());
 
-	snprintf(cmd, sizeof cmd, "timeout 180 %s/w6l -o %s %s 2>/dev/null", bin, co, inputs);
+	snprintf(cmd, sizeof cmd,
+	    "WW_PKGCACHE=%s timeout 300 %s/ww build --sep -o %s "
+	    "%s/selfhost/cmd/%s >/dev/null 2>&1", cache, bin, cstem, cwd, tool);
 	if (runwait(cmd) != 0) {
-		fprintf(stderr, "w6l_ww FAIL: C w6l errored on %s\n", label);
-		unlink(co);
+		fprintf(stderr, "w6l_ww FAIL: C-link sep-build of %s\n", tool);
 		return -1;
 	}
-	snprintf(cmd, sizeof cmd, "timeout 180 %s/w6l_ww -o %s %s 2>/dev/null", bin, wo, inputs);
+	snprintf(cmd, sizeof cmd,
+	    "WW_W6L=%s/w6l_ww WW_PKGCACHE=%s timeout 300 %s/ww build --sep "
+	    "-o %s %s/selfhost/cmd/%s >/dev/null 2>&1",
+	    bin, cache, bin, wstem, cwd, tool);
 	if (runwait(cmd) != 0) {
-		fprintf(stderr, "w6l_ww FAIL: ww w6l errored on %s\n", label);
-		unlink(co); unlink(wo);
+		fprintf(stderr, "w6l_ww FAIL: ww-link sep-build of %s\n", tool);
+		snprintf(cmd, sizeof cmd, "rm -rf %s %s.sepwork", cstem, cstem);
+		if (system(cmd)) {}
 		return -1;
 	}
 	char *bc = NULL, *bw = NULL;
 	size_t nc = 0, nw = 0;
 	int rc = 0;
-	if (slurp(co, &bc, &nc) < 0 || slurp(wo, &bw, &nw) < 0) {
-		fprintf(stderr, "w6l_ww FAIL: cannot read output for %s\n", label);
+	if (slurp(cstem, &bc, &nc) < 0 || slurp(wstem, &bw, &nw) < 0) {
+		fprintf(stderr, "w6l_ww FAIL: cannot read output for %s\n", tool);
 		rc = -1;
 	} else if (nc != nw || memcmp(bc, bw, nc) != 0) {
 		fprintf(stderr, "w6l_ww FAIL: %s — C %zu vs ww %zu bytes\n",
-		    label, nc, nw);
+		    tool, nc, nw);
 		rc = -1;
 	}
 	free(bc); free(bw);
-	unlink(co); unlink(wo);
+	snprintf(cmd, sizeof cmd, "rm -rf %s %s %s.sepwork %s.sepwork",
+	    cstem, wstem, cstem, wstem);
+	if (system(cmd)) {}
 	return rc;
 }
 
@@ -102,36 +119,31 @@ main(void)
 	char cwd[1024];
 	if (getcwd(cwd, sizeof cwd) == NULL) return 1;
 
-	struct {
-		const char *label;
-		const char *inputs_fmt;	/* %s = cwd */
-	} cases[] = {
-		/* Real bootstrap-style links: every selfhost main.o paired
-		 * with libwwrt.a. Exercises both the .o code path and the
-		 * archive two-pass loader (rt_malloc / rt_syscall / rt_abort
-		 * are pulled from libwwrt.a as undefs are encountered). */
-		{ "wwdump+libwwrt",
-		  "%s/selfhost/cmd/wwdump/main.o %s/out/lib/libwwrt.a" },
-		{ "w6a+libwwrt",
-		  "%s/selfhost/cmd/w6a/main.o %s/out/lib/libwwrt.a" },
-		{ "w6l+libwwrt",
-		  "%s/selfhost/cmd/w6l/main.o %s/out/lib/libwwrt.a" },
-		{ NULL, NULL },
-	};
+	/* Real bootstrap-style links: each selfhost tool's full sep build
+	 * (root .o + reverse-topo dep .a set + libwwrt.a). One shared
+	 * pkgcache across all builds so each tool's second (w6l_ww) build
+	 * re-links only. (wwdump is excluded — it imports the compiler-
+	 * internal cmd packages syntax/check/cgen, which don't resolve
+	 * under the lib-path sep dep scan; w6a/w6l are self-contained
+	 * lib-only tools.) */
+	const char *tools[] = { "w6a", "w6l", NULL };
+	char cache[256];
+	snprintf(cache, sizeof cache, "/tmp/wwl_%d_pkgc", getpid());
 
 	int fail = 0;
 	int n = 0;
-	for (int i = 0; cases[i].label; i++) {
-		char inputs[2048];
-		snprintf(inputs, sizeof inputs, cases[i].inputs_fmt, cwd, cwd);
-		if (diff_one(bin, cases[i].label, inputs) != 0) fail++;
+	for (int i = 0; tools[i]; i++) {
+		if (build_and_diff(bin, cwd, tools[i], cache) != 0) fail++;
 		n++;
 	}
+	char rmc[320];
+	snprintf(rmc, sizeof rmc, "rm -rf %s", cache);
+	if (system(rmc)) {}
 	if (fail) {
 		fprintf(stderr, "w6l_ww: %d/%d diff(s) failed\n", fail, n);
 		return 1;
 	}
-	printf("w6l_ww: byte-identical to C w6l on %d corpus links "
-	    "(.o + libwwrt.a archive resolution)\n", n);
+	printf("w6l_ww: byte-identical to C w6l on %d selfhost tool links "
+	    "(sep root .o + reverse-topo .a set + libwwrt.a)\n", n);
 	return 0;
 }