Correctify instanceof and make it optimizable.

src/x64/macro-assembler-x64.cc

Index: src/x64/macro-assembler-x64.cc
diff --git a/src/x64/macro-assembler-x64.cc b/src/x64/macro-assembler-x64.cc
index 4e651274ba270b41fbbc3a91bace66a7e12bd23f..d2ce171cb101ab8237bd76787c7047cea1131d13 100644
--- a/src/x64/macro-assembler-x64.cc
+++ b/src/x64/macro-assembler-x64.cc
@@ -3456,35 +3456,8 @@ void MacroAssembler::GetMapConstructor(Register result, Register map,
 }
 
 
-void MacroAssembler::TryGetFunctionPrototype(Register function,
-                                             Register result,
-                                             Label* miss,
-                                             bool miss_on_bound_function) {
-  Label non_instance;
-  if (miss_on_bound_function) {
-    // Check that the receiver isn't a smi.
-    testl(function, Immediate(kSmiTagMask));
-    j(zero, miss);
-
-    // Check that the function really is a function.
-    CmpObjectType(function, JS_FUNCTION_TYPE, result);
-    j(not_equal, miss);
-
-    movp(kScratchRegister,
-         FieldOperand(function, JSFunction::kSharedFunctionInfoOffset));
-    // It's not smi-tagged (stored in the top half of a smi-tagged 8-byte
-    // field).
-    TestBitSharedFunctionInfoSpecialField(kScratchRegister,
-        SharedFunctionInfo::kCompilerHintsOffset,
-        SharedFunctionInfo::kBoundFunction);
-    j(not_zero, miss);
-
-    // Make sure that the function has an instance prototype.
-    testb(FieldOperand(result, Map::kBitFieldOffset),
-          Immediate(1 << Map::kHasNonInstancePrototype));
-    j(not_zero, &non_instance, Label::kNear);
-  }
-
+void MacroAssembler::TryGetFunctionPrototype(Register function, Register result,
+                                             Label* miss) {
   // Get the prototype or initial map from the function.
   movp(result,
        FieldOperand(function, JSFunction::kPrototypeOrInitialMapOffset));
@@ -3503,15 +3476,6 @@ void MacroAssembler::TryGetFunctionPrototype(Register function,
   // Get the prototype from the initial map.
   movp(result, FieldOperand(result, Map::kPrototypeOffset));
 
-  if (miss_on_bound_function) {
-    jmp(&done, Label::kNear);
-
-    // Non-instance prototype: Fetch prototype from constructor field
-    // in initial map.
-    bind(&non_instance);
-    GetMapConstructor(result, result, kScratchRegister);
-  }
-
   // All done.
   bind(&done);
 }