Make (some) functions called from builtin functions use the callback's global as receiver.

src/x64/full-codegen-x64.cc

Index: src/x64/full-codegen-x64.cc
diff --git a/src/x64/full-codegen-x64.cc b/src/x64/full-codegen-x64.cc
index 5567df2fa62c1fda148e053137525511bc9509e9..ec71021b3ada90b8ed55c3784fc2fff842d5fae1 100644
--- a/src/x64/full-codegen-x64.cc
+++ b/src/x64/full-codegen-x64.cc
@@ -3518,39 +3518,6 @@ void FullCodeGenerator::EmitFastAsciiArrayJoin(ZoneList<Expression*>* args) {
 }
 
 
-void FullCodeGenerator::EmitIsNativeOrStrictMode(ZoneList<Expression*>* args) {
-  ASSERT(args->length() == 1);
-
-  // Load the function into rax.
-  VisitForAccumulatorValue(args->at(0));
-
-  // Prepare for the test.
-  Label materialize_true, materialize_false;
-  Label* if_true = NULL;
-  Label* if_false = NULL;
-  Label* fall_through = NULL;
-  context()->PrepareTest(&materialize_true, &materialize_false,
-                         &if_true, &if_false, &fall_through);
-
-  // Test for strict mode function.
-  __ movq(rdx, FieldOperand(rax, JSFunction::kSharedFunctionInfoOffset));
-  __ testb(FieldOperand(rdx, SharedFunctionInfo::kStrictModeByteOffset),
-           Immediate(1 << SharedFunctionInfo::kStrictModeBitWithinByte));
-  __ j(not_equal, if_true);
-
-  // Test for native function.
-  __ testb(FieldOperand(rdx, SharedFunctionInfo::kNativeByteOffset),
-           Immediate(1 << SharedFunctionInfo::kNativeBitWithinByte));
-  __ j(not_equal, if_true);
-
-  // Not native or strict-mode function.
-  __ jmp(if_false);
-
-  PrepareForBailoutBeforeSplit(TOS_REG, true, if_true, if_false);
-  context()->Plug(if_true, if_false);
-}
-
-
 void FullCodeGenerator::VisitCallRuntime(CallRuntime* expr) {
   Handle<String> name = expr->name();
   if (name->length() > 0 && name->Get(0) == '_') {