Deprecate the BASE_EMBEDDED macro

This was causing more confusion than benefit, so we're removing it.

It's re-defined to empty for now, to avoid touching the ~100 files which
use it, we can remove it completely during a quiet period when it's less
likely to conflict with other work.

Review-Url: https://codereview.chromium.org/2535383005
Cr-Commit-Position: refs/heads/master@{#41393}

src/allocation.cc

@@ -32,23 +32,6 @@ void Malloced::Delete(void* p) {
 }
 
 
-#ifdef DEBUG
-
-static void* invalid = static_cast<void*>(NULL);
-
-void* Embedded::operator new(size_t size) {
-  UNREACHABLE();
-  return invalid;
-}
-
-
-void Embedded::operator delete(void* p) {
-  UNREACHABLE();
-}
-
-#endif
-
-
 char* StrDup(const char* str) {
   int length = StrLength(str);
   char* result = NewArray<char>(length + 1);

src/allocation.h

@@ -26,24 +26,9 @@ class V8_EXPORT_PRIVATE Malloced {
   static void Delete(void* p);
 };
 
-
-// A macro is used for defining the base class used for embedded instances.
-// The reason is some compilers allocate a minimum of one word for the
-// superclass. The macro prevents the use of new & delete in debug mode.
-// In release mode we are not willing to pay this overhead.
-
-#ifdef DEBUG
-// Superclass for classes with instances allocated inside stack
-// activations or inside other objects.
-class Embedded {
- public:
-  void* operator new(size_t size);
-  void  operator delete(void* p);
-};
-#define BASE_EMBEDDED : public NON_EXPORTED_BASE(Embedded)
-#else
+// DEPRECATED
+// TODO(leszeks): Delete this during a quiet period
 #define BASE_EMBEDDED
-#endif
 
 
 // Superclass for classes only using static method functions.