Support FrameLookup vm test on ARM, requiring among other things:

runtime/vm/simulator_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 <math.h>  // for isnan.
 #include <setjmp.h>
 #include <stdlib.h>
 
 #include "vm/globals.h"
 #if defined(TARGET_ARCH_MIPS)
@@ skipping 519 matching lines @@
   // handling stack overflow exceptions. To be safe in potential
   // stack underflows we also add some underflow buffer space.
   stack_ = new char[(Isolate::GetSpecifiedStackSize() +
                      Isolate::kStackSizeBuffer +
                      kSimulatorStackUnderflowSize)];
   icount_ = 0;
   delay_slot_ = false;
   break_pc_ = NULL;
   break_instr_ = 0;
   last_setjmp_buffer_ = NULL;
+  top_exit_frame_info_ = 0;
 
   // Setup architecture state.
   // All registers are initialized to zero to start with.
   for (int i = 0; i < kNumberOfCpuRegisters; i++) {
     registers_[i] = 0;
   }
   pc_ = 0;
   // The sp is initialized to point to the bottom (high address) of the
   // allocated stack area.
   registers_[SP] = StackTop();
@@ skipping 280 matching lines @@
   } else if (instr->BreakCodeField() == Instr::kRedirectCode) {
     SimulatorSetjmpBuffer buffer(this);
 
     if (!setjmp(buffer.buffer_)) {
       int32_t saved_ra = get_register(RA);
       Redirection* redirection = Redirection::FromBreakInstruction(instr);
       uword external = redirection->external_function();
       if (FLAG_trace_sim) {
         OS::Print("Call to host function at 0x%"Pd"\n", external);
       }
+
+      if (redirection->call_kind() != kLeafRuntimeCall) {
+        // The top_exit_frame_info of the current isolate points to the top of
+        // the simulator stack.
+        ASSERT((StackTop() - Isolate::Current()->top_exit_frame_info()) <
+               Isolate::GetSpecifiedStackSize());
+        // Set the top_exit_frame_info of this simulator to the native stack.
+        set_top_exit_frame_info(reinterpret_cast<uword>(&buffer));
+      }
       if (redirection->call_kind() == kRuntimeCall) {
         NativeArguments arguments;
         ASSERT(sizeof(NativeArguments) == 4*kWordSize);
         arguments.isolate_ = reinterpret_cast<Isolate*>(get_register(A0));
         arguments.argc_tag_ = get_register(A1);
         arguments.argv_ = reinterpret_cast<RawObject*(*)[]>(get_register(A2));
         arguments.retval_ = reinterpret_cast<RawObject**>(get_register(A3));
         SimulatorRuntimeCall target =
             reinterpret_cast<SimulatorRuntimeCall>(external);
         target(arguments);
         set_register(V0, icount_);  // Zap result register from void function.
       } else if (redirection->call_kind() == kLeafRuntimeCall) {
         int32_t a0 = get_register(A0);
         int32_t a1 = get_register(A1);
         int32_t a2 = get_register(A2);
         int32_t a3 = get_register(A3);
         SimulatorLeafRuntimeCall target =
             reinterpret_cast<SimulatorLeafRuntimeCall>(external);
         a0 = target(a0, a1, a2, a3);
         set_register(V0, a0);  // Set returned result from function.
       } else {
         ASSERT(redirection->call_kind() == kNativeCall);
         NativeArguments* arguments;
         arguments = reinterpret_cast<NativeArguments*>(get_register(A0));
         SimulatorNativeCall target =
             reinterpret_cast<SimulatorNativeCall>(external);
         target(arguments);
         set_register(V0, icount_);  // Zap result register from void function.
       }
+      set_top_exit_frame_info(0);
 
       // Zap caller-saved registers, since the actual runtime call could have
       // used them.
       set_register(T0, icount_);
       set_register(T1, icount_);
       set_register(T2, icount_);
       set_register(T3, icount_);
       set_register(T4, icount_);
       set_register(T5, icount_);
       set_register(T6, icount_);
@@ skipping 732 matching lines @@
   // Restore the SP register and return R1:R0.
   set_register(SP, sp_before_call);
   return Utils::LowHighTo64Bits(get_register(V0), get_register(V1));
 }
 
 }  // namespace dart
 
 #endif  // !defined(HOST_ARCH_MIPS)
 
 #endif  // defined TARGET_ARCH_MIPS