fast temp. solution when getting errors using gcc >= 10 & opam switch

gcc.sh

#! /bin/sh

eval /usr/bin/gcc -fcommon '"$@"'

gistfile1.txt

from https://discuss.ocaml.org/t/opam-switch-create-and-gcc10/5864/13?u=farukg
thanks to https://discuss.ocaml.org/u/eduardorfs

To avoid problems with the ecossystem a global wrapper is the best option

```shell
#! /bin/sh

eval /usr/bin/gcc -fcommon '"$@"'
```
at /usr/local/bin/gcc