Subzero, MIPS32: MOVZ instruction encoding

Implements MOVZ instruction encoding

R=stichnot@chromium.org

Review URL: https://codereview.chromium.org/2377783002 .

Patch from Srdjan Obucina <Srdjan.Obucina@imgtec.com>.
diff --git a/src/IceAssemblerMIPS32.h b/src/IceAssemblerMIPS32.h
index ce9511b..c9f097a 100644
--- a/src/IceAssemblerMIPS32.h
+++ b/src/IceAssemblerMIPS32.h
@@ -191,6 +191,8 @@
 
   void movt(const Operand *OpRd, const Operand *OpRs, const Operand *OpCc);
 
+  void movz(const Operand *OpRd, const Operand *OpRs, const Operand *OpRt);
+
   void movz_d(const Operand *OpFd, const Operand *OpFs, const Operand *OpFt);
 
   void movz_s(const Operand *OpFd, const Operand *OpFs, const Operand *OpFt);