MIPS: Add rounding support in simulator and RINT instruction.

src/mips64/assembler-mips64.h

Index: src/mips64/assembler-mips64.h
diff --git a/src/mips64/assembler-mips64.h b/src/mips64/assembler-mips64.h
index 70f2eefd41bbe174938f7d0607062c3bad4e6975..4e434f2f0a21f5f0c25249e7d936eab4c60778bf 100644
--- a/src/mips64/assembler-mips64.h
+++ b/src/mips64/assembler-mips64.h
@@ -942,6 +942,10 @@ class Assembler : public AssemblerBase {
   void floor_w_d(FPURegister fd, FPURegister fs);
   void ceil_w_s(FPURegister fd, FPURegister fs);
   void ceil_w_d(FPURegister fd, FPURegister fs);
+  void rint_s(FPURegister fd, FPURegister fs);
+  void rint_d(FPURegister fd, FPURegister fs);
+  void rint(SecondaryField fmt, FPURegister fd, FPURegister fs);
+
 
   void cvt_l_s(FPURegister fd, FPURegister fs);
   void cvt_l_d(FPURegister fd, FPURegister fs);