[PATCH] [libcxx] Consolidate new/delete replacement in tests and disable it when using sanitizers.

[Eric Fiselier]

================
Comment at: test/support/count_new.hpp:8
@@ +7,3 @@
+
+int new_called = 0;
+int delete_called = 0;
----------------
jroelofs wrote:
> For avoidance of macros, how about something like this:
> 
>     class MemCounter {
>     private:
>       int new_called;
>     public:
>       bool checkNewCallsEq(int N) {
>     #if !__has_feature(address_sanitizer) && !__has_feature(memory_sanitizer)
>         return new_called == N;
>     #else
>         return true;
>     #endif
>       }
>     };
> 
>     MemCounter globalMemCounter; 
> 
>     #if !__has_feature(address_sanitizer) && !__has_feature(memory_sanitizer)
>     void* operator new(std::size_t s) throw(std::bad_alloc) {
>         ...
>     }
>     #endif
> 
> And then in the individual tests:
> 
>     assert(globalMemCounter.checkNewCallsEq(0));
> 
> And then if we want to be even more fancy later on, the MemCounter objects could be set up to count only within a scope by allowing them to register with each other to listen for these events. That seems like it'd be beneficial for at least `utilities/memory/util.smartptr/util.smartptr.shared/util.smartptr.shared.create/make_shared.pass.cpp`, and possibly others.
I like it! Much cleaner than what we have now. Thanks!

http://reviews.llvm.org/D6562