Do not call reinterpret_cast when converting from NULL.

If NULL is a nullptr (such as on my FreeBSD system), it is not possible to
use reinterpret_cast to convert it to another pointer. Plus, just using NULL
directly achieves the same effect.

R=ulan@chromium.org

Review URL: https://chromiumcodereview.appspot.com/19388005

Patch from Raphael Kubo da Costa <raphael.kubo.da.costa@intel.com>.

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@15705 ce2b1a6d-e550-0410-aec6-3dcde31c8c00

src/heap.cc

@@ -7350,7 +7350,7 @@ void HeapIterator::reset() {
 
 #ifdef DEBUG
 
-Object* const PathTracer::kAnyGlobalObject = reinterpret_cast<Object*>(NULL);
+Object* const PathTracer::kAnyGlobalObject = NULL;
 
 class PathTracer::MarkVisitor: public ObjectVisitor {
  public:

src/stub-cache.cc

@@ -1539,7 +1539,7 @@ Handle<Code> StubCompiler::GetCodeWithFlags(Code::Flags flags,
                                             Handle<Name> name) {
   return (FLAG_print_code_stubs && !name.is_null() && name->IsString())
       ? GetCodeWithFlags(flags, *Handle<String>::cast(name)->ToCString())
-      : GetCodeWithFlags(flags, reinterpret_cast<char*>(NULL));
+      : GetCodeWithFlags(flags, NULL);
 }