Actually compare each version to the version of the last chosen one.
There's no guarantee that the added test case does showcase the
previous issue (it depends on the order that directory entries
are returned when iterating), but with the issue fixed it should behave
deterministically in any case.
Also improve the match patterns in the mingw-sysroot.cpp test a bit.
Differential Revision: https://reviews.llvm.org/D102873
Previously it would only accept a string as a GCC version if it had
either two components and no suffix, or three components with an
optional suffix.
Debian and ubuntu provided mingw compilers have lib/gcc/target entries
like "5.3-posix" and "5.3-win32". This doesn't try to make any specific
preference between them (other than lexical sorting of the suffix).
Differential Revision: https://reviews.llvm.org/D45505
llvm-svn: 330696
Martin Storsjö