Disable warnings for casting pointers to integers, there is nothing wrong with that.

Signed-off-by: Michael Niedermayer <michaelni@gmx.at>

configure

@@ -3017,6 +3017,7 @@ check_cflags -Wwrite-strings
 check_cflags -Wtype-limits
 check_cflags -Wundef
 check_cflags -Wmissing-prototypes
+check_cflags -Wno-pointer-to-int-cast
 enabled extra_warnings && check_cflags -Winline
 
 # add some linker flags