Cleanup unnecessary duplication of runtime functions.

src/x64/code-stubs-x64.cc

Index: src/x64/code-stubs-x64.cc
diff --git a/src/x64/code-stubs-x64.cc b/src/x64/code-stubs-x64.cc
index 4efbc69776309e74777544d691ae4ae883bd3187..20bc660bfb4a986b0f60bcd9c54fc161fc2459bc 100644
--- a/src/x64/code-stubs-x64.cc
+++ b/src/x64/code-stubs-x64.cc
@@ -592,7 +592,7 @@ void ArgumentsAccessStub::GenerateReadElement(MacroAssembler* masm) {
   __ PopReturnAddressTo(rbx);
   __ Push(rdx);
   __ PushReturnAddressFrom(rbx);
-  __ TailCallRuntime(Runtime::kGetArgumentsProperty, 1, 1);
+  __ TailCallRuntime(Runtime::kArguments, 1, 1);
 }
 
 
@@ -3275,7 +3275,7 @@ void SubStringStub::Generate(MacroAssembler* masm) {
 
   // Just jump to runtime to create the sub string.
   __ bind(&runtime);
-  __ TailCallRuntime(Runtime::kSubStringRT, 3, 1);
+  __ TailCallRuntime(Runtime::kSubString, 3, 1);
 
   __ bind(&single_char);
   // rax: string
@@ -3512,7 +3512,7 @@ void StringCompareStub::Generate(MacroAssembler* masm) {
   // Call the runtime; it returns -1 (less), 0 (equal), or 1 (greater)
   // tagged as a small integer.
   __ bind(&runtime);
-  __ TailCallRuntime(Runtime::kStringCompareRT, 2, 1);
+  __ TailCallRuntime(Runtime::kStringCompare, 2, 1);
 }
 
 
@@ -3810,7 +3810,7 @@ void CompareICStub::GenerateStrings(MacroAssembler* masm) {
   if (equality) {
     __ TailCallRuntime(Runtime::kStringEquals, 2, 1);
   } else {
-    __ TailCallRuntime(Runtime::kStringCompareRT, 2, 1);
+    __ TailCallRuntime(Runtime::kStringCompare, 2, 1);
   }
 
   __ bind(&miss);