[ic] Move KeyedStoreIC::GenerateSlow() to ic-XXX.cc to avoid code duplication.

src/builtins/builtins-handler.cc

Index: src/builtins/builtins-handler.cc
diff --git a/src/builtins/builtins-handler.cc b/src/builtins/builtins-handler.cc
index 63fdffdc636d19c909d5d0008c22239107f8d139..0b831653380590c05834b6fc8bb139b6c5b03442 100644
--- a/src/builtins/builtins-handler.cc
+++ b/src/builtins/builtins-handler.cc
@@ -49,7 +49,7 @@ void Builtins::Generate_KeyedStoreIC_Miss(MacroAssembler* masm) {
 }
 
 void Builtins::Generate_KeyedStoreIC_Slow(MacroAssembler* masm) {
-  ElementHandlerCompiler::GenerateStoreSlow(masm);
+  KeyedStoreIC::GenerateSlow(masm);
 }
 
 void Builtins::Generate_LoadGlobalIC_Miss(CodeStubAssembler* assembler) {