PR libffi/70024
* Makefile.am (libffi_version_script): New.
(libffi_version_dep): New.
(libffi_version_info): New.
(libffi_la_LDFLAGS): Include libffi_version_info, libffi_version_script.
(libffi_la_DEPENDENCIES): Include libffi_version_dep.
* acinclude.m4 (LIBAT_ENABLE, LIBAT_CHECK_LINKER_FEATURES): New.
(LIBAT_ENABLE_SYMVERS, LIBAT_BUILD_VERSIONED_SHLIB): New.
(LIBAT_BUILD_VERSIONED_SHLIB_GNU): New.
(LIBAT_BUILD_VERSIONED_SHLIB_SUN): New.
* configure.ac: Invoke LIBAT_ENABLE_SYMVERS.
* libffi.map: New file.
* libtool-version: Increase to 5.0.0.
* Makefile.in, configure: Rebuild.
* man/Makefile.in, testsuite/Makefile.in: Rebuild.
git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@233921 138bc75d-0d04-0410-961f-82ee72b054a4