Use MemOperand directly to load argv on arm.

Review URL: http://codereview.chromium.org/570003

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@3783 ce2b1a6d-e550-0410-aec6-3dcde31c8c00

src/arm/codegen-arm.cc

@@ -6478,8 +6478,7 @@ void JSEntryStub::GenerateBody(MacroAssembler* masm, bool is_construct) {
   // r1: function
   // r2: receiver
   // r3: argc
-  __ add(r4, sp, Operand((kNumCalleeSaved + 1)*kPointerSize));
-  __ ldr(r4, MemOperand(r4));  // argv
+  __ ldr(r4, MemOperand(sp, (kNumCalleeSaved + 1) * kPointerSize));  // argv
 
   // Push a frame with special values setup to mark it as an entry frame.
   // r0: code entry