xbps-src: multiple performance improvements.

- use xbps-checkvers(1) to resolve dependencies.
- all dependencies are installed at once for the host and target.
- the `show-build-deps` target is now much faster.
- the `update-bulk/show-repo-updates` targets are now much faster.
- the `update-sys/show-sys-updates` targets are now much faster.
- the `bootstrap` target now works on musl hosts.
- simplified some loops.
- use cut(1) rather than awk(1) where applicable.
- multiple random changes to improve performance.

Based on work started by @Duncaen on https://github.com/void-linux/void-packages/pull/12433

Close https://github.com/void-linux/void-packages/pull/12433
Close https://github.com/void-linux/void-packages/pull/11282

common/xbps-src/shutils/bulk.sh

@@ -1,36 +1,11 @@
 # vim: set ts=4 sw=4 et:
 
-bulk_getlink() {
-    local p="${1##*/}"
-    local target="$(readlink $XBPS_SRCPKGDIR/$p)"
-
-    if [ $? -eq 0 -a -n "$target" ]; then
-        p=$target
-    fi
-    echo $p
-}
-
 bulk_sortdeps() {
     local _pkgs _pkg pkgs pkg found f x tmpf
 
-    _pkgs="$@"
-    # Iterate over the list and make sure that only real pkgs are
-    # added to our pkglist.
-    for pkg in ${_pkgs}; do
-        found=0
-        f=$(bulk_getlink $pkg)
-        for x in ${pkgs}; do
-            if [ "$x" = "${f}" ]; then
-                found=1
-                break
-            fi
-        done
-        if [ $found -eq 0 ]; then
-            pkgs+="${f} "
-        fi
-    done
-
+    pkgs="$@"
     tmpf=$(mktemp) || exit 1
+
     # Now make the real dependency graph of all pkgs to build.
     # Perform a topological sort of all pkgs but only with build dependencies
     # that are found in previous step.
@@ -38,16 +13,11 @@ bulk_sortdeps() {
         _pkgs="$(./xbps-src show-build-deps $pkg 2>/dev/null)"
         found=0
         for x in ${_pkgs}; do
-            _pkg=$(bulk_getlink $x)
             for f in ${pkgs}; do
-                if [ "${f}" != "${_pkg}" ]; then
-                    continue
-                fi
-                found=1
-                echo "${pkg} ${f}" >> $tmpf
+                [[ $f == $x ]] && found=1 && echo "${pkg} ${f}" >> $tmpf
             done
         done
-        [ $found -eq 0 ] && echo "${pkg} ${pkg}" >> $tmpf
+        [[ $found -eq 0 ]] && echo "${pkg} ${pkg}" >> $tmpf
     done
     tsort $tmpf|tac
     rm -f $tmpf
@@ -63,7 +33,7 @@ bulk_build() {
         msg_error "xbps-src: cannot find xbps-checkvers(8) command!\n"
     fi
 
-    bulk_sortdeps "$(xbps-checkvers ${1} --distdir=$XBPS_DISTDIR | awk '{print $2}')"
+    bulk_sortdeps "$(xbps-checkvers -f '%n' ${1} --distdir=$XBPS_DISTDIR)"
 }
 
 bulk_update() {