Fix dash AT_EACCESS usage

The dash shell used AT_EACCESS for certain operations, such as when
checking if a file is executable. This does not work on Android 6+,
and is not needed on Termux as a single-user system anyways, so
remove the custom define of AT_EACCESS when building and use the
disabled value of 0 from the patched system headers.

Fixes #37.

packages/dash/build.sh

@@ -1,11 +1,9 @@
 TERMUX_PKG_HOMEPAGE=http://gondor.apana.org.au/~herbert/dash/
 TERMUX_PKG_DESCRIPTION="Small POSIX-compliant implementation of /bin/sh"
 TERMUX_PKG_VERSION=0.5.8
-TERMUX_PKG_BUILD_REVISION=1
+TERMUX_PKG_BUILD_REVISION=2
 TERMUX_PKG_SRCURL=http://gondor.apana.org.au/~herbert/dash/files/dash-${TERMUX_PKG_VERSION}.tar.gz
 
-CFLAGS+=" -DAT_EACCESS=0x200"
-
 termux_step_post_make_install () {
 	# Symlink sh -> dash
 	rm -f $TERMUX_PREFIX/bin/sh $TERMUX_PREFIX/share/man/man1/sh.1