Compilation of each header file alone, as a safety check, was removed
when introducing "#pragma once" because we did not have to check for
possible double inclusion. However we still need to compile each
header to make sure they are self-contained.
* tests/sanity/includes.test: Compile each header.
* tests/run.in: Export various compiler and directory flags.
* spot/twaalgos/emptiness_stats.hh, spot/misc/mspool.hh,
spot/misc/fixpool.hh: Include <spot/misc/common.hh>.
* spot/misc/common.hh: Include <cassert>.
* NEWS: Mention the fixed headers.
* tests/run.in: Here. This helps when spins is installed an the tests
actually compile code; we do not want to inherit the -std=c11
-fvisibility=hidden set for compiling Spot.
Those had been incorrectly renamed to buddy/spot/.libs when we rename
the main src/ directory into spot/. This only affected the setting of
DYLD_LIBRARY_PATH, that used to be needed on Darwin.
* doc/org/.dir-locals.el.in, doc/org/init.el.in, python/ajax/spotcgi.in,
tests/run.in: Fix the PATH.
