w6c+selfhost: same-module preference for bare-leaf lookup

test/wcc/data/samemodprefer/mod1/mod1.ww

@@ -0,0 +1,18 @@
+// samemodprefer/mod1 — exports a `read` that takes an i32 plus a
+// `caller` that invokes bare `read(1i32)`. The bare-leaf lookup must
+// resolve to mod1.read (i32 → i32) rather than mod2.read (str → i32),
+// which coexists in the flat scope. Pre-fix the lookup picked
+// whichever entry hashed earliest into the bucket; a wrong bind would
+// surface as a check-time signature mismatch. Paired with mod2/mod2.ww
+// and test/wcc/697_samemod_prefer.c.
+
+export fn read(x: i32) i32 = {
+	return x + 100i32;
+};
+
+export fn caller() i32 = {
+	// Bare-leaf call inside mod1: must bind to mod1.read (i32 arg).
+	// If preference doesn't kick in this fails check: mod2.read
+	// expects a str, so `read(1i32)` would be a signature mismatch.
+	return read(1i32);
+};