VM: Improve and fix double negation on MIPS.

runtime/vm/disassembler_mips.cc

 // 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.
 
 #include "vm/disassembler.h"
 
 #include "vm/globals.h"  // Needed here to get TARGET_ARCH_MIPS.
 #if defined(TARGET_ARCH_MIPS)
 #include "platform/assert.h"
 
@@ skipping 525 matching lines @@
         break;
       }
       case COP1_SQRT: {
         Format(instr, "sqrt.'fmt 'fd, 'fs");
         break;
       }
       case COP1_MOV: {
         Format(instr, "mov.'fmt 'fd, 'fs");
         break;
       }
+      case COP1_NEG: {
+        Format(instr, "neg.'fmt 'fd, 'fs");
+        break;
+      }
       case COP1_C_F: {
         Format(instr, "c.f.'fmt 'fs, 'ft");
         break;
       }
       case COP1_C_UN: {
         Format(instr, "c.un.'fmt 'fs, 'ft");
         break;
       }
       case COP1_C_EQ: {
         Format(instr, "c.eq.'fmt 'fs, 'ft");
@@ skipping 210 matching lines @@
   decoder.InstructionDecode(instr);
   OS::SNPrint(hex_buffer, hex_size, "%08x", instr->InstructionBits());
   if (out_instr_len) {
     *out_instr_len = Instr::kInstrSize;
   }
 }
 
 }  // namespace dart
 
 #endif  // defined TARGET_ARCH_MIPS