[asan darwin] Allow clients to implement `__sanitizer_report_error_summary`

`__sanitizer_report_error_summary` is declared `llvm/llvm-project/compiler-rt/lib/sanitizer_common/sanitizer_interface_internal.h` as being able to be overridden by the client. On darwin the sanitizer runtime uses this symbol to find references to the sanitizer libraries, so if you override it you end up with the error `=ERROR: Interceptors are not working. This may be because AddressSanitizer is loaded too late (e.g. via dlopen). Please launch the executable with:` at launch time.

Replace uses of `__sanitizer_report_error_summary` for finding the sanitizer libraries with using the address of a local function.

Reviewed By: yln, vitalybuka

Differential Revision: https://reviews.llvm.org/D144830