[wasm][asm.js] Permit ternary operator in asm.js returns in some cases.

test/cctest/asmjs/test-asm-typer.cc

Index: test/cctest/asmjs/test-asm-typer.cc
diff --git a/test/cctest/asmjs/test-asm-typer.cc b/test/cctest/asmjs/test-asm-typer.cc
index 892c968d1d3e0ebb48fd036dec23c2aece3e87db..f2cfe997b9c4d0341c9d5226291e9a6bd87f314f 100644
--- a/test/cctest/asmjs/test-asm-typer.cc
+++ b/test/cctest/asmjs/test-asm-typer.cc
@@ -856,9 +856,10 @@ TEST(ErrorsInFunction) {
        "}\n",
        "Undeclared identifier in return statement"},
       {"function f() {\n"
+       "  var i = 0;\n"
        "  return i?0:1;\n"
        "}\n",
-       "Invalid return type expression"},
+       "Type mismatch in return statement"},
       {"function f() {\n"
        "  return stdlib.Math.E;"
        "}\n",