[wasm] [asm.js] Don't allow bad return types from a global constant

test/mjsunit/asm/asm-validation.js

Index: test/mjsunit/asm/asm-validation.js
diff --git a/test/mjsunit/asm/asm-validation.js b/test/mjsunit/asm/asm-validation.js
index 158187a7966b53606eb5c923741a386b8f010360..06799dab67a3cb53c9209c87d061acba3125f58d 100644
--- a/test/mjsunit/asm/asm-validation.js
+++ b/test/mjsunit/asm/asm-validation.js
@@ -283,3 +283,15 @@ function assertValidAsm(func) {
   assertValidAsm(Module);
   assertEquals(123, m.foo());
 })();
+
+(function TestBadConstUnsignedReturn() {
+  function Module() {
+    "use asm";
+    const i = 0xffffffff;
+    function foo() { return i; }
+    return { foo: foo };
+  }
+  var m = Module();
+  assertTrue(%IsNotAsmWasmCode(Module));
+  assertEquals(0xffffffff, m.foo());
+})();