Fix location of libiberty for resolveAddressToLine - fix Gdb build under clang
libiberty gets installed in lib64 directory under gcc and under lib directory in clang. No idea why.
This fixes the error. I confirmed that it installs correctly under gcc 6.2 and clang 3.9.
Requirement for a clang build of master - see ATLINFR-928.
Edited by Stewart Martin-Haugh