Remove HCompareConstantEqAndBranch (never used), and its corresponding Lithium instructions.

src/mips/lithium-codegen-mips.cc

 // Copyright 2012 the V8 project authors. All rights reserved.
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
 //       notice, this list of conditions and the following disclaimer.
 //     * Redistributions in binary form must reproduce the above
 //       copyright notice, this list of conditions and the following
 //       disclaimer in the documentation and/or other materials provided
@@ skipping 2222 matching lines @@
 
 
 void LCodeGen::DoCmpObjectEqAndBranch(LCmpObjectEqAndBranch* instr) {
   Register left = ToRegister(instr->left());
   Register right = ToRegister(instr->right());
 
   EmitBranch(instr, eq, left, Operand(right));
 }
 
 
-void LCodeGen::DoCmpConstantEqAndBranch(LCmpConstantEqAndBranch* instr) {
-  Register left = ToRegister(instr->left());
-
-  EmitBranch(instr, eq, left, Operand(instr->hydrogen()->right()));
-}
-
-
 Condition LCodeGen::EmitIsObject(Register input,
                                  Register temp1,
                                  Register temp2,
                                  Label* is_not_object,
                                  Label* is_object) {
   __ JumpIfSmi(input, is_not_object);
 
   __ LoadRoot(temp2, Heap::kNullValueRootIndex);
   __ Branch(is_object, eq, input, Operand(temp2));
 
@@ skipping 3564 matching lines @@
   __ Subu(scratch, result, scratch);
   __ lw(result, FieldMemOperand(scratch,
                                 FixedArray::kHeaderSize - kPointerSize));
   __ bind(&done);
 }
 
 
 #undef __
 
 } }  // namespace v8::internal