Find compiler version-specific output files automatically
Also, clean up the way we find the output file. From the comment: # Finding the sample output. The filename is of the form # # <test>.stdout[-<compiler>][-<version>][-<wordsize>][-<platform>] # # and we pick the most specific version available. The <version> is # the major version of the compiler (e.g. 6.8.2 would be "6.8"). For # more fine-grained control use if_compiler_lt(). I'll update the wiki too.