Remove CheckNotRegistersEqual regexp-masm function from all architectures.

src/ia32/regexp-macro-assembler-ia32.cc

Index: src/ia32/regexp-macro-assembler-ia32.cc
diff --git a/src/ia32/regexp-macro-assembler-ia32.cc b/src/ia32/regexp-macro-assembler-ia32.cc
index 0029f33b1a36d5d3c3e7d631d2e4e0e92b759297..45f9531fca588d7f4575d23e4d8e2317237cbe48 100644
--- a/src/ia32/regexp-macro-assembler-ia32.cc
+++ b/src/ia32/regexp-macro-assembler-ia32.cc
@@ -482,15 +482,6 @@ void RegExpMacroAssemblerIA32::CheckNotBackReference(
 }
 
 
-void RegExpMacroAssemblerIA32::CheckNotRegistersEqual(int reg1,
-                                                      int reg2,
-                                                      Label* on_not_equal) {
-  __ mov(eax, register_location(reg1));
-  __ cmp(eax, register_location(reg2));
-  BranchOrBacktrack(not_equal, on_not_equal);
-}
-
-
 void RegExpMacroAssemblerIA32::CheckNotCharacter(uint32_t c,
                                                  Label* on_not_equal) {
   __ cmp(current_character(), c);