Fix plugin testsuite, remove uses of TODO_dump_func (PR testsuite/52948)

Fix plugin testsuite, remove uses of TODO_dump_func (PR testsuite/52948)

	* lib/plugin-support.exp (plugin-test-execute): Properly determine
	testcase name.
	Use fail, pass instead of unresolved.
	Don't log $optstr.

	PR testsuite/52948
	* g++.dg/plugin/dumb_plugin.c (pass_dumb_plugin_example): Remove
	TODO_dump_func.
	* g++.dg/plugin/selfassign.c (pass_warn_self_assign): Likewise.
	* gcc.dg/plugin/one_time_plugin.c (one_pass): Likewise.
	* gcc.dg/plugin/selfassign.c (pass_warn_self_assign): Likewise.

From-SVN: r186490