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

src/ia32/lithium-ia32.cc

Index: src/ia32/lithium-ia32.cc
diff --git a/src/ia32/lithium-ia32.cc b/src/ia32/lithium-ia32.cc
index 20d0a98ebb0ef23c306a64fa213d75de4f3cf371..5c5b774b36ea30243473ca0560d85191d3323a0b 100644
--- a/src/ia32/lithium-ia32.cc
+++ b/src/ia32/lithium-ia32.cc
@@ -1741,13 +1741,6 @@ LInstruction* LChunkBuilder::DoCompareObjectEqAndBranch(
 }
 
 
-LInstruction* LChunkBuilder::DoCompareConstantEqAndBranch(
-  HCompareConstantEqAndBranch* instr) {
-  return new(zone()) LCmpConstantEqAndBranch(
-      UseRegisterAtStart(instr->value()));
-}
-
-
 LInstruction* LChunkBuilder::DoIsObjectAndBranch(HIsObjectAndBranch* instr) {
   ASSERT(instr->value()->representation().IsSmiOrTagged());
   LOperand* temp = TempRegister();