[asm.js] Ensure proper encapsulation of "asmjs" component.

This makes sure that only the "asm-js.h" header is exposed to outside
the directory holding the asm.js validator. It ensures that internals
don't leak out of that component, unless they are explicitly exposed
through the defined interface.

R=clemensh@chromium.org
BUG=v8:6127

Change-Id: I7c41782254cfce102af8edf4356205cfca904e60
Reviewed-on: https://chromium-review.googlesource.com/496147Reviewed-by: Clemens Hammacher <clemensh@chromium.org>
Commit-Queue: Michael Starzinger <mstarzinger@chromium.org>
Cr-Commit-Position: refs/heads/master@{#45125}

src/DEPS

 include_rules = [
   "+base/trace_event/common/trace_event_common.h",
   "+src",
+  "-src/asmjs",
+  "+src/asmjs/asm-js.h",
   "-src/compiler",
   "+src/compiler/pipeline.h",
   "+src/compiler/code-assembler.h",

src/asmjs/asm-js.h

@@ -5,6 +5,8 @@
 #ifndef V8_ASMJS_ASM_JS_H_
 #define V8_ASMJS_ASM_JS_H_
 
+// Clients of this interface shouldn't depend on lots of asmjs internals.
+// Do not include anything from src/asmjs here!
 #include "src/globals.h"
 
 namespace v8 {

src/asmjs/asm-names.h

@@ -108,4 +108,4 @@
   V(kUnsigned, -3, "{unsigned value}")   \
   V(kDouble, -4, "{double value}")
 
-#endif
+#endif  // V8_ASMJS_ASM_NAMES_H_

src/asmjs/asm-types.h

@@ -2,8 +2,8 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-#ifndef SRC_ASMJS_ASM_TYPES_H_
-#define SRC_ASMJS_ASM_TYPES_H_
+#ifndef V8_ASMJS_ASM_TYPES_H_
+#define V8_ASMJS_ASM_TYPES_H_
 
 #include <string>
 
@@ -347,4 +347,4 @@ class V8_EXPORT_PRIVATE AsmType {
 }  // namespace internal
 }  // namespace v8
 
-#endif  // SRC_ASMJS_ASM_TYPES_H_
+#endif  // V8_ASMJS_ASM_TYPES_H_

src/asmjs/switch-logic.h

@@ -2,8 +2,8 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-#ifndef V8_WASM_SWITCH_LOGIC_H
-#define V8_WASM_SWITCH_LOGIC_H
+#ifndef V8_ASMJS_SWITCH_LOGIC_H
+#define V8_ASMJS_SWITCH_LOGIC_H
 
 #include "src/globals.h"
 #include "src/zone/zone-containers.h"
@@ -25,8 +25,9 @@ struct CaseNode : public ZoneObject {
 };
 
 V8_EXPORT_PRIVATE CaseNode* OrderCases(ZoneVector<int>* cases, Zone* zone);
+
 }  // namespace wasm
 }  // namespace internal
 }  // namespace v8
 
-#endif
+#endif  // V8_ASMJS_SWITCH_LOGIC_H