MIPS: Make the mips port build cleanly with clang.

src/mips/macro-assembler-mips.cc

Index: src/mips/macro-assembler-mips.cc
diff --git a/src/mips/macro-assembler-mips.cc b/src/mips/macro-assembler-mips.cc
index 271c6d8cd5d7ef94f227ac8ba876402ac1ed83be..12e10250457c524089aef687c601bcc2e4c8cff3 100644
--- a/src/mips/macro-assembler-mips.cc
+++ b/src/mips/macro-assembler-mips.cc
@@ -1928,7 +1928,7 @@ void MacroAssembler::BranchShort(Label* L, Condition cond, Register rs,
                                  BranchDelaySlot bdslot) {
   BRANCH_ARGS_CHECK(cond, rs, rt);
 
-  int32_t offset;
+  int32_t offset = 0;
   Register r2 = no_reg;
   Register scratch = at;
   if (rt.is_reg()) {
@@ -2361,7 +2361,7 @@ void MacroAssembler::BranchAndLinkShort(Label* L, Condition cond, Register rs,
                                         BranchDelaySlot bdslot) {
   BRANCH_ARGS_CHECK(cond, rs, rt);
 
-  int32_t offset;
+  int32_t offset = 0;
   Register r2 = no_reg;
   Register scratch = at;
   if (rt.is_reg()) {
@@ -5514,7 +5514,6 @@ bool AreAliased(Register r1, Register r2, Register r3, Register r4) {
 
 CodePatcher::CodePatcher(byte* address, int instructions)
     : address_(address),
-      instructions_(instructions),
       size_(instructions * Assembler::kInstrSize),
       masm_(NULL, address, size_ + Assembler::kGap) {
   // Create a new macro assembler pointing to the address of the code to patch.