Merge branch 'mh/fix-detect-compilers-with-nondigit-versions'

The detect-compilers script to help auto-tweaking the build system
had trouble working with compilers whose version number has extra
suffixes.  The script has been taught that certain suffixes (like
"-win32" in "gcc 10-win32") can be safely stripped as they share
the same features and bugs with the version without the suffix.

* mh/fix-detect-compilers-with-nondigit-versions:
  Handle some compiler versions containing a dash