build from source fails with GCC >= 10

[fizwit]

Compile Error
Pointer retuned from a mismatch allocation function. Error is enabled with GCC 10 or greater with [-Werror=mismatched-new-delete]
Memory allocated with new is being "freed" with free(). Memory allocated with <new()> should be "freed" with <delete()>

Steps to reproduce the behavior:
Use GCC 10 or greater
git clone
cd ivar
./autogen.sh
./configure
make

ivar.cpp:502:11: error: ‘void free(void*)’ called on pointer returned from a mismatched allocation function [-Werror=mismatched-new-delete]
  502 |       free(files);
      |       ~~~~^~~~~~~

Expected behavior
Should build without compile errors

Platform

• OS: Ubuntu 18.04
• GCC 11.2.0

[cmaceves]

addressed in PR #136