ksh: fix cross build

srcpkgs/ksh/patches/fix-cross.diff

@@ -0,0 +1,9 @@
+--- scripts/libast_prereq.sh.orig	2021-03-31 22:45:26.222481811 +0200
++++ scripts/libast_prereq.sh	2021-03-31 22:45:34.162481713 +0200
+@@ -25,5 +25,5 @@ cd "$MESON_BUILD_ROOT"
+ # Generate header files whose content depends on the current platform.
+ "$MESON_SOURCE_ROOT/scripts/siglist.sh" > features/siglist.h
+ # shellcheck disable=SC2086
+-$CC -D_BLD_DLL $INC_DIRS -std=gnu99 -o "sfinit" "$MESON_SOURCE_ROOT/etc/sfinit.c"
++cc -D_BLD_DLL $INC_DIRS -std=gnu99 -o "sfinit" "$MESON_SOURCE_ROOT/etc/sfinit.c"
+ ./sfinit > features/sfinit.h

srcpkgs/ksh/template

@@ -4,14 +4,15 @@ version=2020.0.0
 revision=1
 wrksrc="ast-${version}"
 build_style=meson
-configure_args="-Dbuild-api-tests=false -Dbuild-api-tests-only=true"
+build_helper="qemu"
+configure_args="-Dbuild-api-tests=false -Dbuild-api-tests-only=true
+ -Dexe_wrapper=qemu-${XBPS_TARGET_QEMU_MACHINE}-static"
 short_desc="AT&T's Korn shell (ksh93)"
 maintainer="Leah Neukirchen <leah@vuxu.org>"
 license="EPL-1.0"
 homepage="http://www.kornshell.com/"
 distfiles="https://github.com/att/ast/archive/${version}.tar.gz"
 checksum=76597c96c4f94423b9225b5de50ea54be08d5bbaa1e0e594a7eec603bd60ecaf
-nocross=yes
 
 register_shell="/bin/ksh"
 alternatives="