Remove CheckNotRegistersEqual regexp-masm function from all architectures.

src/regexp-macro-assembler.h

Index: src/regexp-macro-assembler.h
diff --git a/src/regexp-macro-assembler.h b/src/regexp-macro-assembler.h
index 85874358e5e87722b246bca6fc1e64af751af6ac..cfb51f742b8eed3d1ea2b94db97a107a6a6d9886 100644
--- a/src/regexp-macro-assembler.h
+++ b/src/regexp-macro-assembler.h
@@ -128,10 +128,6 @@ class RegExpMacroAssembler {
   // array, and if the found byte is non-zero, we jump to the on_bit_set label.
   virtual void CheckBitInTable(Handle<ByteArray> table, Label* on_bit_set) = 0;
 
-  virtual void CheckNotRegistersEqual(int reg1,
-                                      int reg2,
-                                      Label* on_not_equal) = 0;
-
   // Checks whether the given offset from the current position is before
   // the end of the string.  May overwrite the current character.
   virtual void CheckPosition(int cp_offset, Label* on_outside_input) {