[committed] libstdc++: Fix aligned formatting of stacktrace_entry and thread::id [PR112564]

[Hans-Peter Nilsson]

> From: Jonathan Wakely <jwakely@redhat.com>
> Date: Thu, 16 Nov 2023 17:20:09 +0000

> 	PR libstdc++/112564
> 	* include/std/stacktrace (formatter::format): Format according
> 	to format-spec.
> 	* include/std/thread (formatter::format): Use _Align_right as
> 	default.
> 	* testsuite/19_diagnostics/stacktrace/output.cc: Check
> 	fill-and-align handling. Change compile test to run.
> 	* testsuite/30_threads/thread/id/output.cc: Check fill-and-align
> 	handling.

You already know this, so JFTR: this introduced a regression
for some targets, logged as PR112630.

Was this change deliberate:

> --- a/libstdc++-v3/testsuite/19_diagnostics/stacktrace/output.cc
> +++ b/libstdc++-v3/testsuite/19_diagnostics/stacktrace/output.cc
> @@ -1,4 +1,5 @@
> -// { dg-do compile { target c++23 } }
> +// { dg-options "-lstdc++exp" }
> +// { dg-do run { target c++23 } }
>  // { dg-require-effective-target stacktrace }
>  // { dg-add-options no_pch }

i.e. changing from dg-compile to dg-run?

I'm guessing so.  Though the changelog entry and post isn't
explicit, the use of VERIFY is rather clear and most tests
in 19_diagnostics/stacktrace are dg-run.

If so, can the "dg-run-ness" of the test please move to a
separate test and let 19_diagnostics/stacktrace/output.cc be
just dg-compile?  This particular test may not warrant the
consideration, but more so a pattern to follow for other
tests.

brgds, H-P
PS. Sorry, I have no idea why regarding the underlying multi-target problem