[wasm] Support validation of asm.js modules with != 3 args.

src/x87/macro-assembler-x87.cc

Index: src/x87/macro-assembler-x87.cc
diff --git a/src/x87/macro-assembler-x87.cc b/src/x87/macro-assembler-x87.cc
index 9ffbf9f34b20d6e4265fd1e3ab3939d70c3cd90f..7e9533f48be9188c3d69c56075a680b7201faef9 100644
--- a/src/x87/macro-assembler-x87.cc
+++ b/src/x87/macro-assembler-x87.cc
@@ -2120,7 +2120,9 @@ void MacroAssembler::CallRuntime(const Runtime::Function* f, int num_arguments,
   // arguments passed in because it is constant. At some point we
   // should remove this need and make the runtime routine entry code
   // smarter.
-  Move(eax, Immediate(num_arguments));
+  if (num_arguments >= 0) {
+    Move(eax, Immediate(num_arguments));
+  }
   mov(ebx, Immediate(ExternalReference(f, isolate())));
   CEntryStub ces(isolate(), 1, save_doubles);
   CallStub(&ces);