[Bug other/81457] New: Inconsistent section flags for section attribute

["joerg at netbsd dot org" <gcc-bugzilla at gcc dot gnu dot org>]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=81457

            Bug ID: 81457
           Summary: Inconsistent section flags for section attribute
           Product: gcc
           Version: 5.4.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: other
          Assignee: unassigned at gcc dot gnu.org
          Reporter: joerg at netbsd dot org
  Target Milestone: ---

Created attachment 41767
  --> https://gcc.gnu.org/bugzilla/attachment.cgi?id=41767&action=edit
Potential fix, relative to GCC 5.4.0.

Assemble the following input for any ELF target:

__attribute__((section("foo1s"))) const int foo1;
__attribute__((section("foo2s"))) const int foo2 = 42;

Note that foo1s has flags "AW", but foo2s has flags "A".

Bug reproduces on the GCC snapshot option of godbolt.org. The attached patch
applies against GCC 5.4.0, it might need shuffling for newer versions. The
additional null checks are required for correct handling of e.g. __thread
variables.