[intrinsics] Nuke the %_StringCharFromCode intrinsic.

src/crankshaft/hydrogen.cc

Index: src/crankshaft/hydrogen.cc
diff --git a/src/crankshaft/hydrogen.cc b/src/crankshaft/hydrogen.cc
index da0ea4c318da50cde89c07f7e86b34a4b7ccf9f8..dd62dcad9e665a3ac777b225988ab1df858c3053 100644
--- a/src/crankshaft/hydrogen.cc
+++ b/src/crankshaft/hydrogen.cc
@@ -12305,16 +12305,6 @@ void HOptimizedGraphBuilder::GenerateStringCharCodeAt(CallRuntime* call) {
 }
 
 
-// Fast support for string.charAt(n) and string[n].
-void HOptimizedGraphBuilder::GenerateStringCharFromCode(CallRuntime* call) {
-  DCHECK(call->arguments()->length() == 1);
-  CHECK_ALIVE(VisitForValue(call->arguments()->at(0)));
-  HValue* char_code = Pop();
-  HInstruction* result = NewUncasted<HStringCharFromCode>(char_code);
-  return ast_context()->ReturnInstruction(result, call->id());
-}
-
-
 // Fast support for SubString.
 void HOptimizedGraphBuilder::GenerateSubString(CallRuntime* call) {
   DCHECK_EQ(3, call->arguments()->length());