Adds Simulator Longjmp and enables many tests for arm64.

runtime/vm/simulator_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.
 
 // Declares a Simulator for ARM64 instructions if we are not generating a native
 // ARM64 binary. This Simulator allows us to run and debug ARM64 code generation
 // on regular desktop machines.
 // Dart calls into generated code by "calling" the InvokeDartCode stub,
 // which will start execution in the Simulator or forwards to the real entry
 // on a ARM64 HW platform.
@@ skipping 70 matching lines @@
     kNativeCall
   };
   static uword RedirectExternalReference(uword function,
                                          CallKind call_kind,
                                          int argument_count);
 
   void Longjmp(uword pc,
                uword sp,
                uword fp,
                RawObject* raw_exception,
-               RawObject* raw_stacktrace) {
-    UNIMPLEMENTED();
-  }
+               RawObject* raw_stacktrace);
 
  private:
   // Known bad pc value to ensure that the simulator does not execute
   // without being properly setup.
   static const uword kBadLR = -1;
   // A pc value used to signal the simulator to stop execution.  Generally
   // the lr is set to this value on transition from native C code to
   // simulated execution, so that the simulator can "return" to the native
   // C code.
   static const uword kEndSimulatingPC = -2;
@@ skipping 100 matching lines @@
   }
 
   friend class SimulatorDebugger;
   friend class SimulatorSetjmpBuffer;
   DISALLOW_COPY_AND_ASSIGN(Simulator);
 };
 
 }  // namespace dart
 
 #endif  // VM_SIMULATOR_ARM64_H_