This patch is fixing those tests:

20_util/to_chars/float128_c++23.cc
std/format/formatter/requirements.cc
std/format/functions/format.cc
std/format/functions/format_to_n.cc
std/format/functions/size.cc
std/format/functions/vformat_to.cc
std/format/string.cc

Note that symbols used in <format> for __ibm128 and __iee128 are untested.

I even wonder if the normal mode ones are because I cannot find the 
symbols used in gnu.ver.


     libstdc++: [_GLIBCXX_INLINE_VERSION] Add to_chars/from_chars 
symbols export

     libstdc++-v3/ChangeLog

             * include/std/format [_GLIBCXX_INLINE_VERSION](to_chars): 
Adapt __asm symbol
             specifications.
             * config/abi/pre/gnu-versioned-namespace.ver: Add 
to_chars/from_chars symbols
             export.

Ok to commit ?

François