[Bug libstdc++/91488] [9/10 Regression] char_traits::length causes "inlining failed in call to always_inline" error with -fgnu-tm -O2 -std=c++17

["cvs-commit at gcc dot gnu.org" <gcc-bugzilla@gcc.gnu.org>]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=91488

--- Comment #11 from CVS Commits <cvs-commit at gcc dot gnu.org> ---
The releases/gcc-9 branch has been updated by Jonathan Wakely
<redi@gcc.gnu.org>:

https://gcc.gnu.org/g:cc44169fc7bc7552eb85f143f4fee9c8bcdd5e49

commit r9-9590-gcc44169fc7bc7552eb85f143f4fee9c8bcdd5e49
Author: Jonathan Wakely <jwakely@redhat.com>
Date:   Thu Jun 17 14:11:22 2021 +0100

    libstdc++: Simplify constexpr checks in std::char_traits [PR 91488]

    This removes the 'static' keyword from the helper functions added by
    r8-1294 to detect whether the char_traits member functions can be
    evaluated at compile time. This prevents the "inlining failed" error
    reported in the PR.

    The new testcase from the PR is added to the libitm testsuite, because
    that's where we can be sure it's OK to use the -fgnu-tm option.

    Signed-off-by: Jonathan Wakely <jwakely@redhat.com>

            PR libstdc++/91488

    libstdc++-v3/ChangeLog:

            * include/bits/char_traits.h (__constant_string_p)
            (__constant_array_p): Give external linkage.

    libitm/ChangeLog:

            * testsuite/libitm.c++/libstdc++-pr91488.C: New test.

    (cherry picked from commit b376b1ef38971b84975ad1540bf5d2ae0b924e76)