build fails with GNU gcc-4.6.3 on Darwin

[Andras Salamon]

In aclocal.m4 there is a snippet that forces
 EXTRA_CFLAGS="-no-cpp-precomp"
whenever the build system is darwin* which means ncurses does not build
with GNU gcc-4.6.3 (for instance, other versions may also be affected).

I removed this setting to build.

diff -ur ncurses-5.9/configure ncurses-5.9.mod/configure
--- ncurses-5.9/configure       2011-04-01 00:35:51.000000000 +0100
+++ ncurses-5.9.mod/configure   2012-12-03 14:06:25.000000000 +0000
@@ -5584,7 +5584,7 @@
                chmod +x mk_shared_lib.sh
                ;;
        darwin*) #(vi
-               EXTRA_CFLAGS="-no-cpp-precomp"
+               #EXTRA_CFLAGS="-no-cpp-precomp"
                CC_SHARED_OPTS="-dynamic"
                MK_SHARED_LIB='${CC} ${CFLAGS} -dynamiclib -install_name 
${libdir}/`basename address@hidden -compatibility_version ${ABI_VERSION} 
-current_version ${ABI_VERSION} -o $@'
                test "$cf_cv_shlib_version" = auto && cf_cv_shlib_version=abi

The way to fix this is probably to check whether the compiler supports
flag -no-cpp-precomp and only set it if it is supported.

-- Andras Salamon                   address@hidden