Add test against Valgrind.

.github/configs

@@ -55,6 +55,9 @@ case "$config" in
 	LIBCRYPTOFLAGS="--without-openssl"
 	TEST_TARGET=t-exec
 	;;
+    valgrind)
+	TEST_TARGET=USE_VALGRIND=1
+	;;
     *)
 	echo "Unknown configuration $config"
 	exit 1

.github/setup_ci.sh

@@ -53,6 +53,9 @@ for TARGET in $TARGETS; do
     libressl-head)
         INSTALL_LIBRESSL_HEAD=yes
        ;;
+    valgrind)
+       PACKAGES="$PACKAGES valgrind"
+       ;;
     *) echo "Invalid option '${TARGET}'"
         exit 1
         ;;

.github/workflows/c-cpp.yml

@@ -20,6 +20,7 @@ jobs:
           - { os: ubuntu-20.04, configs: hardenedmalloc }
           - { os: ubuntu-20.04, configs: libressl-head }
           - { os: ubuntu-20.04, configs: openssl-head }
+          - { os: ubuntu-20.04, configs: valgrind }
           - { os: ubuntu-18.04, configs: kerberos5 }
           - { os: ubuntu-18.04, configs: libedit }
           - { os: ubuntu-18.04, configs: sk }