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

src/mips/lithium-mips.h

Index: src/mips/lithium-mips.h
diff --git a/src/mips/lithium-mips.h b/src/mips/lithium-mips.h
index f7d23af9492683c2d23c5c6d528b41521a2032f7..009daf02dde0690fc18175197c10776f5b2f30fd 100644
--- a/src/mips/lithium-mips.h
+++ b/src/mips/lithium-mips.h
@@ -74,7 +74,6 @@ class LCodeGen;
   V(ClampIToUint8)                              \
   V(ClampTToUint8)                              \
   V(ClassOfTestAndBranch)                       \
-  V(CmpConstantEqAndBranch)                     \
   V(CompareNumericAndBranch)                    \
   V(CmpObjectEqAndBranch)                       \
   V(CmpMapAndBranch)                            \
@@ -881,20 +880,6 @@ class LCmpObjectEqAndBranch: public LControlInstruction<2, 0> {
 };
 
 
-class LCmpConstantEqAndBranch: public LControlInstruction<1, 0> {
- public:
-  explicit LCmpConstantEqAndBranch(LOperand* left) {
-    inputs_[0] = left;
-  }
-
-  LOperand* left() { return inputs_[0]; }
-
-  DECLARE_CONCRETE_INSTRUCTION(CmpConstantEqAndBranch,
-                               "cmp-constant-eq-and-branch")
-  DECLARE_HYDROGEN_ACCESSOR(CompareConstantEqAndBranch)
-};
-
-
 class LIsObjectAndBranch: public LControlInstruction<1, 1> {
  public:
   LIsObjectAndBranch(LOperand* value, LOperand* temp) {