If llvm-ar is installed at arm-pokymllib32-linux-gnueabi-llvm-ar, it may
think it is llvm-lib due to the "lib" substring.
Update the heuristic to make all the following work as intended:
llvm-ar-9
llvm-ranlib.exe
arm-pokymllib32-linux-gnueabi-llvm-ar
arm-pokymllib32-linux-gnueabi-llvm-ar-9
Needs to be lower-cased (+ a test case -- e.g. LLVM-AR.EXE should work)