[Bug c++/100205] [11 Regression] error: invalid use of non-static data member

["gcc-bugs at marehr dot dialup.fu-berlin.de" <gcc-bugzilla@gcc.gnu.org>]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=100205

--- Comment #3 from gcc-bugs at marehr dot dialup.fu-berlin.de ---
To be more precise my gcc build is:

```
> gcc-git -v

Using built-in specs.
COLLECT_GCC=/opt/gcc/gcc-git//bin/g++
COLLECT_LTO_WRAPPER=/opt/gcc/gcc-git/lib/gcc/x86_64-pc-linux-gnu/11.0.1/lto-wrapper
Target: x86_64-pc-linux-gnu
Configured with: /home/marehr/Packages/gcc-git/src/gcc/configure
--prefix=/opt/gcc/gcc-git --libdir=/opt/gcc/gcc-git/lib
--libexecdir=/opt/gcc/gcc-git/lib --mandir=/opt/gcc/gcc-git/share/man
--infodir=/opt/gcc/gcc-git/share/info --with-bugurl=https://bugs.archlinux.org/
--enable-languages=c,c++ --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 --disable-bootstrap
Thread model: posix
Supported LTO compression algorithms: zlib zstd
gcc version 11.0.1 20210421 (prerelease) (GCC) 
COMPILER_PATH=/opt/gcc/gcc-git/lib/gcc/x86_64-pc-linux-gnu/11.0.1/:/opt/gcc/gcc-git/lib/gcc/x86_64-pc-linux-gnu/11.0.1/:/opt/gcc/gcc-git/lib/gcc/x86_64-pc-linux-gnu/:/opt/gcc/gcc-git/lib/gcc/x86_64-pc-linux-gnu/11.0.1/:/opt/gcc/gcc-git/lib/gcc/x86_64-pc-linux-gnu/
LIBRARY_PATH=/opt/gcc/gcc-git/lib/gcc/x86_64-pc-linux-gnu/11.0.1/:/opt/gcc/gcc-git/lib/gcc/x86_64-pc-linux-gnu/11.0.1/../../../../lib/:/lib/../lib/:/usr/lib/../lib/:/opt/gcc/gcc-git/lib/gcc/x86_64-pc-linux-gnu/11.0.1/../../../:/lib/:/usr/lib/
COLLECT_GCC_OPTIONS='-v' '-shared-libgcc' '-mtune=generic' '-march=x86-64'
'-dumpdir' 'a.'
 /opt/gcc/gcc-git/lib/gcc/x86_64-pc-linux-gnu/11.0.1/collect2 -plugin
/opt/gcc/gcc-git/lib/gcc/x86_64-pc-linux-gnu/11.0.1/liblto_plugin.so
-plugin-opt=/opt/gcc/gcc-git/lib/gcc/x86_64-pc-linux-gnu/11.0.1/lto-wrapper
-plugin-opt=-fresolution=/tmp/cchzTpvd.res -plugin-opt=-pass-through=-lgcc_s
-plugin-opt=-pass-through=-lgcc -plugin-opt=-pass-through=-lc
-plugin-opt=-pass-through=-lgcc_s -plugin-opt=-pass-through=-lgcc --build-id
--eh-frame-hdr --hash-style=gnu -m elf_x86_64 -dynamic-linker
/lib64/ld-linux-x86-64.so.2 -pie /lib/../lib/Scrt1.o /lib/../lib/crti.o
/opt/gcc/gcc-git/lib/gcc/x86_64-pc-linux-gnu/11.0.1/crtbeginS.o
-L/opt/gcc/gcc-git/lib/gcc/x86_64-pc-linux-gnu/11.0.1
-L/opt/gcc/gcc-git/lib/gcc/x86_64-pc-linux-gnu/11.0.1/../../../../lib
-L/lib/../lib -L/usr/lib/../lib
-L/opt/gcc/gcc-git/lib/gcc/x86_64-pc-linux-gnu/11.0.1/../../.. -rpath
/opt/gcc/gcc-git//lib -lstdc++ -lm -lgcc_s -lgcc -lc -lgcc_s -lgcc
/opt/gcc/gcc-git/lib/gcc/x86_64-pc-linux-gnu/11.0.1/crtendS.o
/lib/../lib/crtn.o
/usr/bin/ld: /lib/../lib/Scrt1.o: in function `_start':
(.text+0x24): undefined reference to `main'
collect2: error: ld returned 1 exit status
```

The build gcc-git-11.0.1.r184220.be8d5f99f50 did work, but the newer build
gcc-git-11.0.1.r184427.e826f7355af doesn't any more.