Run Git hooks within xcu4

* build-aux/git-hooks/pre-commit (LC_ALL):
* build-aux/git-hooks/prepare-commit-msg (SHA1): Run using xcu4
tools.

build-aux/git-hooks/pre-commit

@@ -21,6 +21,14 @@
 LC_ALL=C
 export LC_ALL
 
+# If this is a system where /bin/sh isn't sufficient to
+# run git-sh-setup, use a working shell as a recourse.
+if test -x "/usr/xpg4/bin/sh" && test -z "$POSIX_SHELL"; then
+    POSIX_SHELL=1
+    export POSIX_SHELL
+    exec "/usr/xpg4/bin/sh" `dirname $0`/pre-commit
+fi
+
 exec >&2
 
 . git-sh-setup

build-aux/git-hooks/prepare-commit-msg

@@ -25,6 +25,10 @@ SHA1=$3
 # Prefer gawk if available, as it handles NUL bytes properly.
 if type gawk >/dev/null 2>&1; then
   awk="gawk"
+# Next use /usr/xpg4/bin/awk if available, since the script
+# doesn't support Unix awk.
+elif test -x /usr/xpg4/bin/awk; then
+  awk="/usr/xpg4/bin/awk"
 else
   awk="awk"
 fi