Changes for running tests on arm64 hardware.

runtime/vm/assembler_arm64.h

 // Copyright (c) 2014, 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_ARM64_H_
 #define VM_ASSEMBLER_ARM64_H_
 
 #ifndef VM_ASSEMBLER_H_
 #error Do not include assembler_arm64.h directly; use assembler.h instead.
 #endif
@@ skipping 666 matching lines @@
     EmitUnconditionalBranchRegOp(BLR, rn);
   }
   void ret(Register rn = R30) {
     EmitUnconditionalBranchRegOp(RET, rn);
   }
 
   // Exceptions.
   void hlt(uint16_t imm) {
     EmitExceptionGenOp(HLT, imm);
   }
+  void brk(uint16_t imm) {
+    EmitExceptionGenOp(BRK, imm);
+  }
 
   // Double floating point.
   bool fmovdi(VRegister vd, double immd) {
     int64_t imm64 = bit_cast<int64_t, double>(immd);
     const uint8_t bit7 = imm64 >> 63;
     const uint8_t bit6 = (~(imm64 >> 62)) & 0x1;
     const uint8_t bit54 = (imm64 >> 52) & 0x3;
     const uint8_t bit30 = (imm64 >> 48) & 0xf;
     const uint8_t imm8 = (bit7 << 7) | (bit6 << 6) | (bit54 << 4) | bit30;
     const int64_t expimm8 = Instr::VFPExpandImm(imm8);
@@ skipping 973 matching lines @@
                                   Register value,
                                   Label* no_update);
 
   DISALLOW_ALLOCATION();
   DISALLOW_COPY_AND_ASSIGN(Assembler);
 };
 
 }  // namespace dart
 
 #endif  // VM_ASSEMBLER_ARM64_H_