Fix V8_GNUC_PREREQ macro.

TBR=svenpanne@chromium.org

Review URL: https://codereview.chromium.org/21049004

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@15926 ce2b1a6d-e550-0410-aec6-3dcde31c8c00

src/globals.h

@@ -105,7 +105,7 @@
 #elif defined(__GNUC__)
 # define V8_CC_GNU 1
 # define V8_GNUC_PREREQ(major, minor) \
-    ((major) > __GNUC__ || ((major) == __GNUC__ && (minor) >= __GNUC_MINOR__))
+    (__GNUC__ > (major) || (__GNUC__ == (major) && __GNUC_MINOR__ >=  (minor)))
 # if defined(__MINGW64__)
 #  define V8_CC_MINGW 1
 #  define V8_CC_MINGW64 1