Add OpEndIT() for marking the end of OpIT blocks

In ARM we need to prevent code motion to the inside of an
IT block.  This was done using a GenBarrier() to mark the end, but
it wasn't obvious that this is what was happening.  This CL adds
an explicit OpEndIT() that takes the LIR of the OpIT for future
checks.

Bug: 13751744
Change-Id: If41d2adea1f43f11ebb3b72906bd308252ce3d01
diff --git a/compiler/dex/quick/mips/codegen_mips.h b/compiler/dex/quick/mips/codegen_mips.h
index c962ea3..5089111 100644
--- a/compiler/dex/quick/mips/codegen_mips.h
+++ b/compiler/dex/quick/mips/codegen_mips.h
@@ -157,6 +157,7 @@
     LIR* OpDecAndBranch(ConditionCode c_code, RegStorage reg, LIR* target);
     LIR* OpFpRegCopy(RegStorage r_dest, RegStorage r_src);
     LIR* OpIT(ConditionCode cond, const char* guide);
+    void OpEndIT(LIR* it);
     LIR* OpMem(OpKind op, RegStorage r_base, int disp);
     LIR* OpPcRelLoad(RegStorage reg, LIR* target);
     LIR* OpReg(OpKind op, RegStorage r_dest_src);