* * fix regression: -d:nimHasLibFFI was not being tested anymore,
in part because testament was silently treating some errors as easy to overlook messages
* turned that message into an error
* -d:nimHasLibFFI is now being tested with nim cpp
* use correct signatures for importc procs
* workaround for openbsd to unblock ctffi testing
* fix https://github.com/timotheecour/Nim/issues/152 `^[[0m` is inserted in stderr for `echo code | nim c -`
* resetAttributes not even needed, already handled in styledWriteLine
* simplify tests in tests/trunner.nim thanks to this fix
* -d:checkabi obsolete (ABI check now enforced); add `addTypeHeader` helper
* cleanups
* import sizeof at CT for {.completeType.}
* address comments; revert default enabling of -d:checkAbi for now
* mimportc_size_check.nim => msizeof5.nim; merge mabi_check.nim into msizeof5.nim; refactor
* all pragmas in errmsgs should be written: '.importc' (un-ambiguous and less verbose than {.importc.})
