[wasm] Acquire the context for TrapIf from a wasm frame

This is the first step to reduce the size of the out-of-line code of
TrapIf. Instead of passing the context to the runtime call as a
parameter, we pass Smi::kZero to the runtime call and then get the
actual context from the WasmFrame on the stack.

BUG=v8:5908
R=titzer@chromium.org, clemensh@chromium.org

Review-Url: https://codereview.chromium.org/2664273002
Cr-Commit-Position: refs/heads/master@{#42853}

src/compiler/arm/code-generator-arm.cc

@@ -1930,7 +1930,7 @@ void CodeGenerator::AssembleArchTrap(Instruction* instr,
             ExternalReference::wasm_call_trap_callback_for_testing(isolate()),
             0);
       } else {
-        __ Move(cp, isolate()->native_context());
+        __ Move(cp, Smi::kZero);
         gen_->AssembleSourcePosition(instr_);
         __ CallRuntime(trap_id);
       }

src/compiler/arm64/code-generator-arm64.cc

@@ -1739,7 +1739,7 @@ void CodeGenerator::AssembleArchTrap(Instruction* instr,
             0);
       } else {
         DCHECK(csp.Is(__ StackPointer()));
-        __ Move(cp, isolate()->native_context());
+        __ Move(cp, Smi::kZero);
         // Initialize the jssp because it is required for the runtime call.
         __ Mov(jssp, csp);
         gen_->AssembleSourcePosition(instr_);

src/compiler/ia32/code-generator-ia32.cc

@@ -1714,7 +1714,7 @@ void CodeGenerator::AssembleArchTrap(Instruction* instr,
             ExternalReference::wasm_call_trap_callback_for_testing(isolate()),
             0);
       } else {
-        __ Move(esi, isolate()->native_context());
+        __ Move(esi, Smi::kZero);
         gen_->AssembleSourcePosition(instr_);
         __ CallRuntime(trap_id);
       }

src/compiler/mips/code-generator-mips.cc

@@ -1778,7 +1778,7 @@ void CodeGenerator::AssembleArchTrap(Instruction* instr,
             ExternalReference::wasm_call_trap_callback_for_testing(isolate()),
             0);
       } else {
-        __ Move(cp, isolate()->native_context());
+        __ Move(cp, Smi::kZero);
         gen_->AssembleSourcePosition(instr_);
         __ CallRuntime(trap_id);
       }

src/compiler/mips64/code-generator-mips64.cc

@@ -2113,7 +2113,7 @@ void CodeGenerator::AssembleArchTrap(Instruction* instr,
             ExternalReference::wasm_call_trap_callback_for_testing(isolate()),
             0);
       } else {
-        __ Move(cp, isolate()->native_context());
+        __ Move(cp, Smi::kZero);
         gen_->AssembleSourcePosition(instr_);
         __ CallRuntime(trap_id);
       }

src/compiler/wasm-compiler.cc

@@ -91,7 +91,9 @@ Node* BuildCallToRuntime(Runtime::FunctionId f, JSGraph* jsgraph,
   inputs[count++] = jsgraph->ExternalConstant(
       ExternalReference(f, jsgraph->isolate()));         // ref
   inputs[count++] = jsgraph->Int32Constant(fun->nargs);  // arity
-  inputs[count++] = jsgraph->HeapConstant(context);      // context
+  inputs[count++] = context.is_null()
+                        ? jsgraph->SmiConstant(0)
+                        : jsgraph->HeapConstant(context);  // context
   inputs[count++] = *effect_ptr;
   inputs[count++] = control;
 
@@ -328,7 +330,7 @@ class WasmTrapHelper : public ZoneObject {
       Node* parameters[] = {trap_reason_smi,     // message id
                             trap_position_smi};  // byte position
       BuildCallToRuntime(Runtime::kThrowWasmError, jsgraph(),
-                         module->instance->context, parameters,
+                         Handle<Context>::null(), parameters,
                          arraysize(parameters), effect_ptr, *control_ptr);
     }
     if (false) {

src/compiler/x64/code-generator-x64.cc

@@ -2342,7 +2342,7 @@ void CodeGenerator::AssembleArchTrap(Instruction* instr,
             ExternalReference::wasm_call_trap_callback_for_testing(isolate()),
             0);
       } else {
-        __ Move(rsi, isolate()->native_context());
+        __ Move(rsi, Smi::kZero);
         gen_->AssembleSourcePosition(instr_);
         __ CallRuntime(trap_id);
       }

src/runtime/runtime-wasm.cc

@@ -55,6 +55,14 @@ RUNTIME_FUNCTION(Runtime_WasmGrowMemory) {
 Object* ThrowRuntimeError(Isolate* isolate, int message_id, int byte_offset,
                           bool patch_source_position) {
   HandleScope scope(isolate);
+  DCHECK_NULL(isolate->context());
+  StackFrameIterator it(isolate);
+  it.Advance();
+  CHECK(it.frame()->is_wasm_compiled());
+  isolate->set_context(*WasmCompiledFrame::cast(it.frame())
+                            ->wasm_instance()
+                            ->compiled_module()
+                            ->native_context());
   Handle<Object> error_obj = isolate->factory()->NewWasmRuntimeError(
       static_cast<MessageTemplate::Template>(message_id));