Implements intrinsics for MIPS.

runtime/vm/assembler_mips.h

Index: runtime/vm/assembler_mips.h
===================================================================
--- runtime/vm/assembler_mips.h	(revision 23484)
+++ runtime/vm/assembler_mips.h	(working copy)
@@ -187,10 +187,7 @@
   // Only the tags field of the object is initialized.
   void TryAllocate(const Class& cls,
                    Label* failure,
-                   bool near_jump,
-                   Register instance_reg) {
-    UNIMPLEMENTED();
-  }
+                   Register instance_reg);
 
   // Debugging and bringup support.
   void Stop(const char* message);
@@ -523,6 +520,14 @@
     EmitFpuLoadStore(LWC1, ft, addr);
   }
 
+  void madd(Register rs, Register rt) {
+    EmitRType(SPECIAL2, rs, rt, R0, 0, MADD);
+  }
+
+  void maddu(Register rs, Register rt) {
+    EmitRType(SPECIAL2, rs, rt, R0, 0, MADDU);
+  }
+
   void mfc1(Register rt, FRegister fs) {
     Emit(COP1 << kOpcodeShift |
          COP1_MF << kCop1SubShift |
@@ -567,6 +572,14 @@
          fs << kFsShift);
   }
 
+  void mthi(Register rs) {
+    EmitRType(SPECIAL, rs, R0, R0, 0, MTHI);
+  }
+
+  void mtlo(Register rs) {
+    EmitRType(SPECIAL, rs, R0, R0, 0, MTLO);
+  }
+
   void muld(DRegister dd, DRegister ds, DRegister dt) {
     FRegister fd = static_cast<FRegister>(dd * 2);
     FRegister fs = static_cast<FRegister>(ds * 2);