[build2] build2 staging GCC 11 compiler warnings

[Boris Kolpackov]

Matthew Krupcale via users <users at build2.org> writes:

> On Tue, Jan 26, 2021 at 8:35 AM Boris Kolpackov <boris at codesynthesis.com> wrote:
> > That's unfortunate. Am I understanding correctly from your logs that
> > this warning is enabled with just -Wall?
> 
> It looks like -Wfree-nonheap-object is enabled by default actually[1].
> 
> [1] https://gcc.gnu.org/onlinedocs/gcc/Warning-Options.html

Found this bug report: https://gcc.gnu.org/bugzilla/show_bug.cgi?id=98753

Skimming through it, it looks like this check is now enabled in more
contexts (besides operator delete) which is causing more false positives.

Do you think you could create a preprocessed TU for one of the cases
that trigger this warning in build2 and attach it to the bug report
as another example?