Allow the embedder to pass the virtual memory limit to v8

src/spaces.h

Index: src/spaces.h
diff --git a/src/spaces.h b/src/spaces.h
index 908e723827586d8af2bcfb3d798def1defab4539..1fb856265bcb2ed1dce6d91d9deeeb15bf9e1569 100644
--- a/src/spaces.h
+++ b/src/spaces.h
@@ -946,7 +946,7 @@ class CodeRange {
   // Reserves a range of virtual memory, but does not commit any of it.
   // Can only be called once, at heap initialization time.
   // Returns false on failure.
-  bool SetUp(const size_t requested_size);
+  bool SetUp(size_t requested_size);
 
   // Frees the range of virtual memory, and frees the data structures used to
   // manage it.