automake: add missing AC_MSG_RESULT calls to AM_SANITY_CHECK. From https://bugs.gnu.org/76448 (automake-patches). * m4/sanity.m4 (AM_SANITY_CHECK): Call AC_MSG_RESULT before erroring out so that a complete line is printed to stdout before the error message is written to stderr. * NEWS: mention this. * THANKS: add Richard.