Some other compilers turn too many warnings into errors with this flag.
Originally committed as revision 22276 to svn://svn.ffmpeg.org/ffmpeg/trunk
check_cflags -Wtype-limits
check_cflags -Wundef
check_cflags -Wmissing-prototypes
-check_cflags -Werror=implicit
enabled extra_warnings && check_cflags -Winline
# add some linker flags
add_cflags -msg_disable unreachcode
elif enabled gcc; then
check_cflags -fno-tree-vectorize
+ check_cflags -Werror=implicit
elif enabled clang; then
check_cflags -Qunused-arguments
elif enabled armcc; then