Revert dcf6955: Fix V8 mingw32 build

Patch has been merged upstream in V8 3.4.6.

Fixes #1351.

deps/v8/src/platform-win32.cc

@@ -118,15 +118,6 @@ int strncasecmp(const char* s1, const char* s2, int n) {
 // the Microsoft Visual Studio C++ CRT.
 #ifdef __MINGW32__
 
-namespace v8 {
-namespace internal {
-
-intptr_t OS::MaxVirtualMemory() {
-  return 0;
-}
-}
-}
-
 int localtime_s(tm* out_tm, const time_t* time) {
   tm* posix_local_time_struct = localtime(time);
   if (posix_local_time_struct == NULL) return 1;