[wasm] Add inspector test for stepping

src/runtime/runtime-wasm.cc

 // Copyright 2016 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "src/runtime/runtime-utils.h"
 
 #include "src/arguments.h"
 #include "src/assembler.h"
 #include "src/compiler/wasm-compiler.h"
 #include "src/conversions.h"
@@ skipping 151 matching lines @@
   Handle<WasmInstanceObject> instance =
       Handle<WasmInstanceObject>::cast(instance_obj);
 
   // The arg buffer is the raw pointer to the caller's stack. It looks like a
   // Smi (lowest bit not set, as checked by IsSmi), but is no valid Smi. We just
   // cast it back to the raw pointer.
   CHECK(!arg_buffer_obj->IsHeapObject());
   CHECK(arg_buffer_obj->IsSmi());
   uint8_t* arg_buffer = reinterpret_cast<uint8_t*>(*arg_buffer_obj);
 
+  // Reset the current isolate's context.
+  isolate->set_context(*instance->compiled_module()->native_context());

[titzer, 2017/01/25 10:04:09]

Do we need to set it back when returning, or will the CEntryStub do that?

[Yang, 2017/01/25 10:12:22]

We have a SaveContext scope. Is that something you should/could use?

[Clemens Hammacher, 2017/01/25 11:41:57]

I am not sure if resetting is needed, but since this is not performance critical
code, I just added a SaveContext scope.

+
   instance->debug_info()->RunInterpreter(func_index, arg_buffer);
   return isolate->heap()->undefined_value();
 }
 
 }  // namespace internal
 }  // namespace v8