pointer/integer comparison blocked in gcc build

[nolash]

../../gcc-6.2.0/gcc/ubsan.c:1472:20: error: ISO C++ forbids comparison between pointer and integer [-fpermissive]
 1472 |       || xloc.file == '\0' || xloc.file[0] == '\xff'

trying to build gcc-6.2.0 with book version GIT-20190419-arm using:

$ gcc -v
Using built-in specs.
COLLECT_GCC=gcc
COLLECT_LTO_WRAPPER=/usr/lib/gcc/x86_64-pc-linux-gnu/10.2.0/lto-wrapper
Target: x86_64-pc-linux-gnu
Configured with: /build/gcc/src/gcc/configure --prefix=/usr --libdir=/usr/lib --libexecdir=/usr/lib --mandir=/usr/share/man --infodir=/usr/share/info --with-bugurl=https://bugs.archlinux.org/ --enable-languages=c,c++,ada,fortran,go,lto,objc,obj-c++,d --with-isl --with-linker-hash-style=gnu --with-system-zlib --enable-__cxa_atexit --enable-cet=auto --enable-checking=release --enable-clocale=gnu --enable-default-pie --enable-default-ssp --enable-gnu-indirect-function --enable-gnu-unique-object --enable-install-libiberty --enable-linker-build-id --enable-lto --enable-multilib --enable-plugin --enable-shared --enable-threads=posix --disable-libssp --disable-libstdcxx-pch --disable-libunwind-exceptions --disable-werror gdc_include_dir=/usr/include/dlang/gdc
Thread model: posix
Supported LTO compression algorithms: zlib zstd
gcc version 10.2.0 (GCC)
$ uname -omr
5.11.13-arch1-1 x86_64 GNU/Linux
$ printenv | grep CLFS
CLFS_FLOAT=hard
CLFS_TARGET=arm-linux-musleabihf
CLFS_FPU=vfpv4
CLFS_ARCH=arm
CLFS_ARM_ARCH=armv8-a
CLFS=/home/clfs/lfs
CLFS_HOST=x86_64-cross-linux-gnu

[nolash]

This seems to help to get past it:

qca/open-ath9k-htc-firmware#135 (comment)