X87: Move function prototype handling into a special handler rather than IC

port r22526.

original commit message:
  Move function prototype handling into a special handler rather than IC

  Adjust hydrogen handling of function.prototype to be based on map feedback.
  Handle non-instance prototype loading using an IC rather than in the hydrogen
  instruction. In the future, remove the special instruction and replace by multiple
  hydrogen instructions.

BUG=
R=verwaest@chromium.org

Review URL: https://codereview.chromium.org/410203002

Patch from Chunyang Dai <chunyang.dai@intel.com>.

git-svn-id: https://v8.googlecode.com/svn/branches/bleeding_edge@22585 ce2b1a6d-e550-0410-aec6-3dcde31c8c00

src/x87/lithium-codegen-x87.cc

@@ -3131,16 +3131,6 @@ void LCodeGen::DoLoadFunctionPrototype(LLoadFunctionPrototype* instr) {
   Register temp = ToRegister(instr->temp());
   Register result = ToRegister(instr->result());
 
-  // Check that the function really is a function.
-  __ CmpObjectType(function, JS_FUNCTION_TYPE, result);
-  DeoptimizeIf(not_equal, instr->environment());
-
-  // Check whether the function has an instance prototype.
-  Label non_instance;
-  __ test_b(FieldOperand(result, Map::kBitFieldOffset),
-            1 << Map::kHasNonInstancePrototype);
-  __ j(not_zero, &non_instance, Label::kNear);
-
   // Get the prototype or initial map from the function.
   __ mov(result,
          FieldOperand(function, JSFunction::kPrototypeOrInitialMapOffset));
@@ -3156,12 +3146,6 @@ void LCodeGen::DoLoadFunctionPrototype(LLoadFunctionPrototype* instr) {
 
   // Get the prototype from the initial map.
   __ mov(result, FieldOperand(result, Map::kPrototypeOffset));
-  __ jmp(&done, Label::kNear);
-
-  // Non-instance prototype: Fetch prototype from constructor field
-  // in the function's map.
-  __ bind(&non_instance);
-  __ mov(result, FieldOperand(result, Map::kConstructorOffset));
 
   // All done.
   __ bind(&done);