Cleanup unnecessary duplication of runtime functions.

src/runtime/runtime-strings.cc

Index: src/runtime/runtime-strings.cc
diff --git a/src/runtime/runtime-strings.cc b/src/runtime/runtime-strings.cc
index 3b9cfbf969d7d305670cab1226dfb3186b3b3a23..d49d6607b0092f6d44cf1f2a9b4a5a4fc80a100d 100644
--- a/src/runtime/runtime-strings.cc
+++ b/src/runtime/runtime-strings.cc
@@ -281,7 +281,7 @@ RUNTIME_FUNCTION(Runtime_StringLocaleCompare) {
 }
 
 
-RUNTIME_FUNCTION(Runtime_SubStringRT) {
+RUNTIME_FUNCTION(Runtime_SubString) {
   HandleScope scope(isolate);
   DCHECK(args.length() == 3);
 
@@ -309,13 +309,7 @@ RUNTIME_FUNCTION(Runtime_SubStringRT) {
 }
 
 
-RUNTIME_FUNCTION(Runtime_SubString) {
-  SealHandleScope shs(isolate);
-  return __RT_impl_Runtime_SubStringRT(args, isolate);
-}
-
-
-RUNTIME_FUNCTION(Runtime_StringAddRT) {
+RUNTIME_FUNCTION(Runtime_StringAdd) {
   HandleScope scope(isolate);
   DCHECK(args.length() == 2);
   CONVERT_ARG_HANDLE_CHECKED(String, str1, 0);
@@ -328,12 +322,6 @@ RUNTIME_FUNCTION(Runtime_StringAddRT) {
 }
 
 
-RUNTIME_FUNCTION(Runtime_StringAdd) {
-  SealHandleScope shs(isolate);
-  return __RT_impl_Runtime_StringAddRT(args, isolate);
-}
-
-
 RUNTIME_FUNCTION(Runtime_InternalizeString) {
   HandleScope handles(isolate);
   RUNTIME_ASSERT(args.length() == 1);
@@ -428,7 +416,7 @@ RUNTIME_FUNCTION(Runtime_CharFromCode) {
 }
 
 
-RUNTIME_FUNCTION(Runtime_StringCompareRT) {
+RUNTIME_FUNCTION(Runtime_StringCompare) {
   HandleScope handle_scope(isolate);
   DCHECK(args.length() == 2);
 
@@ -497,12 +485,6 @@ RUNTIME_FUNCTION(Runtime_StringCompareRT) {
 }
 
 
-RUNTIME_FUNCTION(Runtime_StringCompare) {
-  SealHandleScope shs(isolate);
-  return __RT_impl_Runtime_StringCompareRT(args, isolate);
-}
-
-
 RUNTIME_FUNCTION(Runtime_StringBuilderConcat) {
   HandleScope scope(isolate);
   DCHECK(args.length() == 3);