test all possible SIMD archtectures in Vector's testsuite

[Roland Haas]

Currently Vectors only tests the “default” SIMD architecture which is usually the “best” one a given processors supports. This however leaves less often used architectures untested eg. single precision ones or ones supported by old processors.

The pull request https://bitbucket.org/cactuscode/cactusutils/pull-requests/26/rhaas-testall/diff uses some include file trickery to test all possible architectures.

[Roland Haas]

Please review.

[Roland Haas]

Unless objected I will apply this after 2020-06-01.

[Roland Haas]

Applied as git hash 00918e9 "Vectors: do not write parfile in test" of cactusutils