[Bug c++/114357] New: C++: Support the no_destroy attribute

[i at maskray dot me]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=114357

            Bug ID: 114357
           Summary: C++: Support the no_destroy attribute
           Product: gcc
           Version: unknown
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: c++
          Assignee: unassigned at gcc dot gnu.org
          Reporter: i at maskray dot me
  Target Milestone: ---

Clang supports [[clang::no_destroy]] (alternative form:
`__attribute__((no_destroy))`) to disable exit-time destructors of variables of
static or thread local storage duration.

* July 2018 discussion:
https://discourse.llvm.org/t/rfc-suppress-c-static-destructor-registration/49128
* Patch: https://reviews.llvm.org/D50994 with follow-up
https://reviews.llvm.org/D54344
* Current documentation:
https://clang.llvm.org/docs/AttributeReference.html#no-destroy
* https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2018/p1247r0.html (seems
not presented to EWG yet)

[[clang::always_destroy]] enables exit-time destructors for specific objects
(when -fno-c++-static-destructors disables exit-time destructors globally).