[Bug libstdc++/124714] std module (std.cc) should check for long double support

[garcia.6l20 at gmail dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=124714

--- Comment #11 from Garcia Sylvain <garcia.6l20 at gmail dot com> ---
Created attachment 64108
  --> https://gcc.gnu.org/bugzilla/attachment.cgi?id=64108&action=edit
output.ii

Command:
/opt/tpl/arm-none-eabi/bin/arm-none-eabi-g++ \
    -mcpu=cortex-m33 \
    -march=armv8-m.main+dsp+fp \
    -mfloat-abi=hard \
    -specs=picolibcpp.specs \
    -E -dD -x c++ /dev/null > output.ii