gcc-runtime: Fix __FILE__ related reproducablity issues
libstdc++ uses assertion macros which use __FILE__ macros and
if (__builtin_expect(!bool(_Condition), false)) \
std::__replacement_assert(__FILE__, __LINE__, __PRETTY_FUNCTION__, \
#_Condition)
This ends up using absolute paths into build tree for the cases where
the charconv header is used, therefore replace the file prefix paths
with on-target paths to make them build dir independent
Signed-off-by: Khem Raj <raj.khem@gmail.com> Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>
