Fix missing cases of empty_string canonicalization

src/arm/macro-assembler-arm.cc

Index: src/arm/macro-assembler-arm.cc
diff --git a/src/arm/macro-assembler-arm.cc b/src/arm/macro-assembler-arm.cc
index 7400337489a5fa6c6bdfc9d51a8743f9d13540d8..71645019478449a8e0c69da58bc4f4e190b82607 100644
--- a/src/arm/macro-assembler-arm.cc
+++ b/src/arm/macro-assembler-arm.cc
@@ -1537,21 +1537,6 @@ void MacroAssembler::EnterExitFrame(bool save_doubles, int stack_space,
   str(ip, MemOperand(fp, ExitFrameConstants::kSPOffset));
 }
 
-
-void MacroAssembler::InitializeNewString(Register string,
-                                         Register length,
-                                         Heap::RootListIndex map_index,
-                                         Register scratch1,
-                                         Register scratch2) {
-  SmiTag(scratch1, length);
-  LoadRoot(scratch2, map_index);
-  str(scratch1, FieldMemOperand(string, String::kLengthOffset));
-  mov(scratch1, Operand(String::kEmptyHashField));
-  str(scratch2, FieldMemOperand(string, HeapObject::kMapOffset));
-  str(scratch1, FieldMemOperand(string, String::kHashFieldOffset));
-}
-
-
 int MacroAssembler::ActivationFrameAlignment() {
 #if V8_HOST_ARCH_ARM
   // Running on the real platform. Use the alignment as mandated by the local