[Bug c/123527] New: Add __builtin_is_modifiable_lvalue

[pinskia at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=123527

            Bug ID: 123527
           Summary: Add __builtin_is_modifiable_lvalue
           Product: gcc
           Version: 16.0
            Status: UNCONFIRMED
          Severity: enhancement
          Priority: P3
         Component: c
          Assignee: unassigned at gcc dot gnu.org
          Reporter: pinskia at gcc dot gnu.org
  Target Milestone: ---

https://forge.sourceware.org/pinskia/gcc-TEST/src/branch/is_lvalue

I thought I file this one to keep track of it. Because I kept on forgetting
about it and I didn't submit it during stage 1 of GCC 16. Hopefully I or
someone on my team will have time to submit for stage 1 of GCC 17.
Though I am wondering if this is needed for the Linux kernel any more since
there has not been any changes on the clang side for a while.