[PATCH v2] libstdc++: Export explicit instantiations for C++20 members of std::string

[Rainer Orth]

Hi Tomasz,

>> Please ignore this last change, and test only the two above.
>
> looks good: builds are in stage 2 now.

while there were not Solaris-specific regressions, the original patch
caused this regression

+FAIL: g++.dg/lto/20091022-2 cp_lto_20091022-2_0.o assemble, -O3 -flto -Winline
+FAIL: g++.dg/lto/20091022-2 cp_lto_20091022-2_0.o-cp_lto_20091022-2_0.o link, -O3 -flto -Winline

In file included from i386-pc-solaris2.11/libstdc++-v3/include/string:58,
                 from /vol/gcc/src/hg/master/local/gcc/testsuite/g++.dg/lto/20091022-2_0.C:5:
In member function 'std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> >::~basic_string()',
    inlined from 'main' at /vol/gcc/src/hg/master/local/gcc/testsuite/g++.dg/lto/20091022-2_0.C:12:1:
i386-pc-solaris2.11/libstdc++-v3/include/bits/basic_string.h:295:7: warning: inlining failed in call to 'std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> >::_M_dispose()': call is unlikely and code size would grow [-Winline]
i386-pc-solaris2.11/libstdc++-v3/include/bits/basic_string.h:920:19: note: called from here

apparently everywhere: seen on i386-pc-solaris2.11,
sparc-sun-solaris2.11, x86_64-pc-linux-gnu, and i686-pc-linux-gnu.

	Rainer

-- 
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Rainer Orth, Center for Biotechnology, Bielefeld University