Adds support for UseDartApi vm test on MIPS.

runtime/vm/assembler_mips.h

 // Copyright (c) 2013, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 #ifndef VM_ASSEMBLER_MIPS_H_
 #define VM_ASSEMBLER_MIPS_H_
 
 #ifndef VM_ASSEMBLER_H_
 #error Do not include assembler_mips.h directly; use assembler.h instead.
 #endif
@@ skipping 535 matching lines @@
   }
 
   void sw(Register rt, const Address& addr) {
     EmitLoadStore(SW, rt, addr);
   }
 
   void swc1(FRegister ft, const Address& addr) {
     EmitFpuLoadStore(SWC1, ft, addr);
   }
 
+  void xori(Register rt, Register rs, const Immediate& imm) {
+    ASSERT(Utils::IsUint(kImmBits, imm.value()));
+    const uint16_t imm_value = static_cast<uint16_t>(imm.value());
+    EmitIType(XORI, rs, rt, imm_value);
+  }
+
   void xor_(Register rd, Register rs, Register rt) {
     EmitRType(SPECIAL, rs, rt, rd, 0, XOR);
   }
 
   // Macros in alphabetical order.
 
   // Addition of rs and rt with the result placed in rd.
   // After, ro < 0 if there was signed overflow, ro >= 0 otherwise.
   // rd and ro must not be TMP1 or TMP2.
   // ro must be different from all the other registers.
   void AdduDetectOverflow(Register rd, Register rs, Register rt, Register ro);
 
   // ro must be different from rd and rs.
   // rd and ro must not be TMP1 or TMP2
   void AddImmediateDetectOverflow(Register rd, Register rs, int32_t imm,
                                   Register ro) {
     LoadImmediate(rd, imm);
     AdduDetectOverflow(rd, rs, rd, ro);
   }
 
+  // Subtraction of rt from rs (rs - rt) with the result placed in rd.
+  // After, ro < 0 if there was signed overflow, ro >= 0 otherwise.
+  // None of rd, rs, rt, or ro may be TMP1.
+  // ro must be different from the other registers.
+  void SubuDetectOverflow(Register rd, Register rs, Register rt, Register ro);
+
   void Branch(const ExternalLabel* label) {
     LoadImmediate(TMP1, label->address());
     jr(TMP1);
   }
 
   void BranchPatchable(const ExternalLabel* label) {
     const uint16_t low = Utils::Low16Bits(label->address());
     const uint16_t high = Utils::High16Bits(label->address());
     lui(TMP1, Immediate(high));
     ori(TMP1, TMP1, Immediate(low));
@@ skipping 350 matching lines @@
     delay_slot_available_ = true;
   }
 
   DISALLOW_ALLOCATION();
   DISALLOW_COPY_AND_ASSIGN(Assembler);
 };
 
 }  // namespace dart
 
 #endif  // VM_ASSEMBLER_MIPS_H_