Fix the Cygwin build after isolates merge.

Patch by Bert Belder.

Review URL: http://codereview.chromium.org/6776011

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@7447 ce2b1a6d-e550-0410-aec6-3dcde31c8c00

test/cctest/test-alloc.cc

@@ -200,6 +200,7 @@ TEST(CodeRange) {
       size_t allocated = 0;
       void* base = Isolate::Current()->code_range()->
           AllocateRawMemory(requested, &allocated);
+      CHECK(base != NULL);
       blocks.Add(Block(base, static_cast<int>(allocated)));
       current_allocated += static_cast<int>(allocated);
       total_allocated += static_cast<int>(allocated);