build: Allow alphanumeric test name suffixes

To allow test names to be more descriptive, allow a suffix to be
added to the numeric name of the test.  e.g. a test can be named
"tests/generic/001-some-descriptive-name".

Name suffixes are limited to alphanumeric characters and dash - the
name is always prefixed with an unique id for easy identification
of a specific test. Hence we can still use shorthand forms such as
"generic/001" when referring to a test and be clearly understood.

Signed-off-by: Jan Tulak <jtulak@redhat.com>
Reviewed-by: Eryu Guan <eguan@redhat.com>
Reviewed-by: David Sterba <dsterba@suse.cz>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Signed-off-by: Dave Chinner <david@fromorbit.com>

common/rc

@@ -22,6 +22,16 @@
 
 BC=$(which bc 2> /dev/null) || BC=
 
+# Valid test names start with 3 digits "NNN":
+#  "[0-9]\{3\}"
+# followed by an optional "-":
+#  "-\?"
+# followed by an optional combination of alphanumeric and "-" chars:
+#  "[[:alnum:]-]*"
+# e.g. 999-the-mark-of-fstests
+#
+VALID_TEST_NAME="[0-9]\{3\}-\?[[:alnum:]-]*"
+
 _require_math()
 {
 	if [ -z "$BC" ]; then