gcc: gcc 6.3.0 fix comparison between pointer and integer
Fix FS#832
/source/build_dir/toolchain-mips_74kc_gcc-6.3.0_musl/gcc-6.3.0/gcc/ubsan.c:
In function 'bool ubsan_use_new_style_p(location_t)':
/source/build_dir/toolchain-mips_74kc_gcc-6.3.0_musl/gcc-6.3.0/gcc/ubsan.c:1474:23:
error: ISO C++ forbids comparison between pointer and integer
[-fpermissive]
|| xloc.file == '\0' || xloc.file[0] == '\xff'
^~~~
make[5]: *** [Makefile:1085: ubsan.o] Error 1
https://www.viva64.com/en/b/0425/#ID0EMGCI
Signed-off-by: Kevin Darbyshire-Bryant <kevin@darbyshire-bryant.me.uk>