wcc/cgen: handle def-str field access (.ptr/.len) on Sdef ident

selfhost/cmd/wcc/cgenexpr.ww

@@ -499,6 +499,34 @@ fn cgdot(c: *cgen, n: *node) void = {
 			};
 		};
 	};
+	// `def NAME: str = "..."` field access — inline the literal.
+	// Sdef-backed strs aren't laid out in memory, so falling
+	// through to the SB-load fallback below would mis-emit
+	// `MOVQ <field>(SB), AX` (looking up the field name as a
+	// symbol). Mirrors cmd/w6c/cgen.c N_DOT off==0 / Sdef branch.
+	if (lhs != nil) {
+		if (lhs.kind == N_IDENT) {
+			let drhs: *node = deflookuprhs(c, lhs.str);
+			if (drhs != nil) {
+				if (drhs.kind == N_STRLIT) {
+					let bytes: str = drhs.str;
+					if (streq(fld, "ptr")) {
+						let lab: str = internstrlit(c, bytes);
+						emitline("\tLEAQ\t");
+						os.write(1, lab.ptr, lab.len: u64);
+						emitline("(SB), AX\n");
+						return;
+					};
+					if (streq(fld, "len")) {
+						emitline("\tMOVQ\t$");
+						emitint(bytes.len: i64);
+						emitline(", AX\n");
+						return;
+					};
+				};
+			};
+		};
+	};
 	// Module-qualified value reference: `mod.name` where `mod`
 	// is N_IDENT bound as SK_USE and the leaf isn't a local.
 	// Treat as a SB symbol — `MOVQ leaf(SB), AX`. Same fallback