m4/ax_append_*_flags.m4: update from upstream
tree9d93b25199ffb7430cfbc86f0cf513b336b0498a
-rw-r--r-- 271 .gitignore
-rw-r--r-- 1822 AUTHORS
-rw-r--r-- 17987 COPYING
-rw-r--r-- 519 INSTALL
-rw-r--r-- 4886 Makefile.am
-rw-r--r-- 8437 NEWS
-rw-r--r-- 1504 README
-rwxr-xr-x 481 autogen.sh
-rw-r--r-- 12485 configure.ac
drwxr-xr-x - doc
drwxr-xr-x - lyrics
drwxr-xr-x - m4
drwxr-xr-x - po
drwxr-xr-x - src
-rwxr-xr-x 1464 test.sh
drwxr-xr-x - test
-rw-r--r-- 7242 valgrind.suppressions