[wasm] [asmjs] Route asm.js warnings to the dev console.

src/asmjs/asm-typer.h

 // 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.
 
 #ifndef SRC_ASMJS_ASM_TYPER_H_
 #define SRC_ASMJS_ASM_TYPER_H_
 
 #include <cstdint>
 #include <string>
 #include <unordered_set>
 
 #include "src/allocation.h"
 #include "src/asmjs/asm-types.h"
 #include "src/ast/ast-type-bounds.h"
 #include "src/ast/ast-types.h"
 #include "src/ast/ast.h"
 #include "src/effects.h"
+#include "src/messages.h"
 #include "src/type-info.h"
 #include "src/zone/zone-containers.h"
 #include "src/zone/zone.h"
 
 namespace v8 {
 namespace internal {
 namespace wasm {
 
 class AsmType;
 class AsmTyperHarnessBuilder;
@@ skipping 35 matching lines @@
     kMathPI,
     kMathSQRT1_2,
     kMathSQRT2,
   };
 
   ~AsmTyper() = default;
   AsmTyper(Isolate* isolate, Zone* zone, Script* script, FunctionLiteral* root);
 
   bool Validate();
 
-  const char* error_message() const { return error_message_; }
+  Handle<JSMessageObject> error_message() const { return error_message_; }
 
   AsmType* TypeOf(AstNode* node) const;
   AsmType* TypeOf(Variable* v) const;
   StandardMember VariableAsStandardMember(Variable* var);
 
   typedef std::unordered_set<StandardMember, std::hash<int> > StdlibSet;
 
   StdlibSet StdlibUses() const { return stdlib_uses_; }
 
   // Each FFI import has a usage-site signature associated with it.
@@ skipping 258 matching lines @@
   // 3 Environments
   ZoneHashMap global_scope_;  // 3.1 Global environment
   ZoneHashMap local_scope_;   // 3.2 Variable environment
 
   std::uintptr_t stack_limit_;
   bool stack_overflow_ = false;
   ZoneMap<AstNode*, AsmType*> node_types_;
   static const int kErrorMessageLimit = 128;
   AsmType* fround_type_;
   AsmType* ffi_type_;
-  char error_message_[kErrorMessageLimit];
+  Handle<JSMessageObject> error_message_;
   StdlibSet stdlib_uses_;
 
   DISALLOW_IMPLICIT_CONSTRUCTORS(AsmTyper);
 };
 
 }  // namespace wasm
 }  // namespace internal
 }  // namespace v8
 
 #endif  // SRC_ASMJS_ASM_TYPER_H_