[lsan] Invoke hooks on realloc

Previously lsan would not invoke hooks on reallocations.
An accompanying regression test is included in sanitizer_common.

This change also moves hook calls to a location where subsequent
calls (via an external caller) to __sanitizer_get_allocated_size
via hooks will return a valid size.

This allows a faster version of __sanitizer_get_allocated_size
to be implemented, which can skip checks.

Test to ensure RunFreeHooks' call order will come with
__sanitizer_get_allocated_size_fast

Differential Revision: https://reviews.llvm.org/D151175