Update the IPO support for GCC and CLANG.
Note that you may need to define "AR", "LD" and "RANLIB", if the names do not match the default ones (clang/llvm are often trailed by version numbers).
Fixes #539 (closed)
Note that you may need to define "AR", "LD" and "RANLIB", if the names do not match the default ones (clang/llvm are often trailed by version numbers).
Fixes #539 (closed)