testing/tcl_commands: test target create, cget, configure

Introduce basic testing of error-handling in target configuration
related commands.

The tests can be run via `make check` when JTAG `dummy` adapter is
enabled.

Change-Id: Id0f382046dd70007d8e696d82d2396a7ccab7a33
Signed-off-by: Evgeniy Naydanov <evgeniy.naydanov@syntacore.com>
Reviewed-on: https://review.openocd.org/c/openocd/+/8644
Tested-by: jenkins
Reviewed-by: Antonio Borneo <borneo.antonio@gmail.com>

testing/tcl_commands/test-target-configure-cget-command.cfg

@@ -0,0 +1,31 @@
+# SPDX-License-Identifier: GPL-2.0-or-later
+
+namespace import testing_helpers::*
+namespace import configure_testing::*
+
+adapter driver dummy
+jtag newtap tap cpu -irlen 5
+
+{*}[target_create_first_args] {*}[simple_configure_options]
+
+set target_name [lindex [target names] 0]
+
+check_matches testee {$target_name cget -type}
+
+foreach {opt arg} [simple_configure_options] {
+	check_syntax_err {$target_name cget $opt extra_arg}
+	check_matches [dict get [simple_configure_options] $opt] \
+		{$target_name cget $opt}
+}
+
+check_error_matches .*-event.* {$target_name cget -event}
+$target_name cget -event examine-start
+check_syntax_err {$target_name cget -event examine-start extra_arg}
+
+check_syntax_err {$target_name configure}
+
+foreach {opt arg} [simple_configure_options] {
+	$target_name configure $opt [$target_name cget $opt]
+}
+
+shutdown