test/928: pin chained-dot index base (o.in_.xs[i]) depth-independence (#48 review)

test/wcc/928_match_nonident_idx_run.c

@@ -19,7 +19,8 @@
  * Rows pin: the discovering repro shape (field-base slice index, all
  * three variants matched both ways), the regex shape (56B-slot
  * inst-like union over r.insts[i]; payload reads stay within the 32B
- * cursor — words past R8 are #43's deferred residual), and the ident
+ * cursor — words past R8 are #43's deferred residual), a chained-dot
+ * base (o.in_.xs[i] — depth independence), and the ident
  * scrutinee / ident-base array + slice index controls (byte-id at
  * master per the #48 scoping probes; cs is untouched by the fix, so
  * the per-row cs==ww cmp pins them unchanged). A call-BASE index
@@ -123,6 +124,32 @@ static const struct row rows[] = {
 	  "    return 0;\n"
 	  "};\n",
 	  0 },
+	/* Dot-DEPTH: the index base is a CHAINED dot (o.in_.xs[i] =
+	 * N_INDEX over N_DOT over N_DOT) — pins that the stamped-carrier
+	 * resolve is depth-independent (any non-ident base shape, not
+	 * just one dot level). */
+	{ "dot_depth_idx",
+	  TU_TYPES
+	  "type inner = struct { xs: []tu, k: size };\n"
+	  "type outer = struct { in_: inner, n: size };\n"
+	  "export fn main() i32 = {\n"
+	  "    let sl: []tu = [(true: vb), ((9: size): vc)];\n"
+	  "    let o: outer;\n"
+	  "    o.in_.xs = sl;\n"
+	  "    o.in_.k = 1;\n"
+	  "    o.n = 2;\n"
+	  "    match (o.in_.xs[0]) {\n"
+	  "    case let b: vb => { if (!(b: bool)) { return 2; }; };\n"
+	  "    case => return 1;\n"
+	  "    };\n"
+	  "    match (o.in_.xs[1]) {\n"
+	  "    case va => return 3;\n"
+	  "    case let s: vc => { if ((s: size) != 9) { return 4; }; };\n"
+	  "    case vb => return 5;\n"
+	  "    };\n"
+	  "    return 0;\n"
+	  "};\n",
+	  0 },
 	/* Controls: ident scrutinee + ident-base array and slice index
 	 * — the pre-existing matchscrutt/cgmatch paths the fix must not
 	 * disturb (asm byte-id at master per the scoping probes). */