[libc++] Avoid destructor call for error_category singletons

When a handle to an error_category singleton object is used during the
termination phase of a program, the destruction of the error_category
object may have occurred prior to execution of the current destructor
or function registered with atexit, because the singleton object may
have been constructed after the corresponding initialization or call
to atexit. For example, the updated tests from this patch will fail if
using a libc++ built using a compiler that updates the vtable of the
object on destruction.

This patch attempts to avoid the issue by causing the destructor to not
be called in the style of ResourceInitHelper in src/experimental/memory_resource.cpp.
This approach might not work if object lifetime is strictly enforced.

Differential Revision: https://reviews.llvm.org/D65667



Co-authored-by: Louis Dionne <ldionne.2@gmail.com>