REL_17_9
Install our "missing" script where PGXS builds can find it.
Update config/ax_pthread.m4 to latest upstream version.
Optimize pg_popcount() with AVX-512 instructions.
All supported systems have locale_t.
Fix configure's AC_CHECK_DECLS tests to work correctly with clang.
Add copyright notices to a few perl scripts that don't have them
Update config.guess and config.sub
Rename configure.in to configure.ac
Fix install-strip on Mac OS X
Don't put library-supplied -L/-I switches before user-supplied ones.
meson: Add initial version of meson based build system
Remove cvs keywords from all files.
Remove MSVC scripts
Fix collection of typos in the code and the documentation
Fix vpath build
Remove distprep
Unify DLSUFFIX on Darwin
configure: More use of AC_ARG_VAR