Changes to run "Hello, world!" on MIPS hardware.

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 785 matching lines @@
     const int32_t ival = bit_cast<int32_t, float>(value);
     if (ival == 0) {
       mtc1(ZR, rd);
     } else {
       LoadImmediate(TMP1, ival);
       mtc1(TMP1, rd);
     }
   }
 
   void AddImmediate(Register rd, Register rs, int32_t value) {
+    if (value == 0) return;
     if (Utils::IsInt(kImmBits, value)) {
       addiu(rd, rs, Immediate(value));
     } else {
       LoadImmediate(TMP1, value);
       addu(rd, rs, TMP1);
     }
   }
 
   void AddImmediate(Register rd, int32_t value) {
     AddImmediate(rd, rd, value);
@@ skipping 355 matching lines @@
                                   Register value,
                                   Label* no_update);
 
   DISALLOW_ALLOCATION();
   DISALLOW_COPY_AND_ASSIGN(Assembler);
 };
 
 }  // namespace dart
 
 #endif  // VM_ASSEMBLER_MIPS_H_