[stubs] Remove dead string copying code

src/ia32/code-stubs-ia32.h

Index: src/ia32/code-stubs-ia32.h
diff --git a/src/ia32/code-stubs-ia32.h b/src/ia32/code-stubs-ia32.h
index c1878f0207ffa3e53749a9e8d4abd2aeaaaf3722..a2dacd32d78b8ec0f44a3457bb82a2e6c69328cc 100644
--- a/src/ia32/code-stubs-ia32.h
+++ b/src/ia32/code-stubs-ia32.h
@@ -16,16 +16,6 @@ void ArrayNativeCode(MacroAssembler* masm,
 
 class StringHelper : public AllStatic {
  public:
-  // Generate code for copying characters using the rep movs instruction.
-  // Copies ecx characters from esi to edi. Copying of overlapping regions is
-  // not supported.
-  static void GenerateCopyCharacters(MacroAssembler* masm,
-                                     Register dest,
-                                     Register src,
-                                     Register count,
-                                     Register scratch,
-                                     String::Encoding encoding);
-
   // Compares two flat one byte strings and returns result in eax.
   static void GenerateCompareFlatOneByteStrings(MacroAssembler* masm,
                                                 Register left, Register right,