[intrinsics] Kill the %_IsMinusZero intrinsic.

src/full-codegen/x64/full-codegen-x64.cc

Index: src/full-codegen/x64/full-codegen-x64.cc
diff --git a/src/full-codegen/x64/full-codegen-x64.cc b/src/full-codegen/x64/full-codegen-x64.cc
index 2ccd288048ebce1e15d48a86fb1cf4ace4e3aebf..a939a8f0a42ce54bbd85970dea77439742dbd73f 100644
--- a/src/full-codegen/x64/full-codegen-x64.cc
+++ b/src/full-codegen/x64/full-codegen-x64.cc
@@ -2889,33 +2889,6 @@ void FullCodeGenerator::EmitIsSimdValue(CallRuntime* expr) {
 }
 
 
-void FullCodeGenerator::EmitIsMinusZero(CallRuntime* expr) {
-  ZoneList<Expression*>* args = expr->arguments();
-  DCHECK(args->length() == 1);
-
-  VisitForAccumulatorValue(args->at(0));
-
-  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);
-
-  Handle<Map> map = masm()->isolate()->factory()->heap_number_map();
-  __ CheckMap(rax, map, if_false, DO_SMI_CHECK);
-  __ cmpl(FieldOperand(rax, HeapNumber::kExponentOffset),
-          Immediate(0x1));
-  __ j(no_overflow, if_false);
-  __ cmpl(FieldOperand(rax, HeapNumber::kMantissaOffset),
-          Immediate(0x00000000));
-  PrepareForBailoutBeforeSplit(expr, true, if_true, if_false);
-  Split(equal, if_true, if_false, fall_through);
-
-  context()->Plug(if_true, if_false);
-}
-
-
 void FullCodeGenerator::EmitIsArray(CallRuntime* expr) {
   ZoneList<Expression*>* args = expr->arguments();
   DCHECK(args->length() == 1);