Add public version macros.

include/v8-version.h

Index: include/v8-version.h
diff --git a/include/v8-version.h b/include/v8-version.h
new file mode 100644
index 0000000000000000000000000000000000000000..8d158179bdcc7dbdb77aae1cb256a720b9fcc7e9
--- /dev/null
+++ b/include/v8-version.h
@@ -0,0 +1,20 @@
+// Copyright 2015 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 V8_INCLUDE_VERSION_H_  // V8_VERSION_H_ conflicts with src/version.h
+#define V8_INCLUDE_VERSION_H_
+
+// These macros define the version number for the current version.
+// NOTE these macros are used by some of the tool scripts and the build
+// system so their names cannot be changed without changing the scripts.
+#define V8_MAJOR_VERSION 4
+#define V8_MINOR_VERSION 3
+#define V8_BUILD_NUMBER 0
+#define V8_PATCH_LEVEL 0
+
+// Use 1 for candidates and 0 otherwise.
+// (Boolean macro values are not supported by all preprocessors.)
+#define V8_IS_CANDIDATE_VERSION 1
+
+#endif  // V8_INCLUDE_VERSION_H_