testsuite: Skip class-11_a.H for default_packed targets

testsuite: Skip class-11_a.H for default_packed targets

The g++.dg/modules/class-11_a.H test expects structs to have a padding.
Skip this test for targets which have packed structs by default.

This patch fixes the test for pru-unknown-elf from FAIL to UNSUPPORTED.
The test still passes on x86_64-linux-gnu.

gcc/testsuite/ChangeLog:

	* g++.dg/modules/class-11_a.H: Skip test for effective
	default_packed targets.
	* g++.dg/modules/class-11_b.C: Ditto.

Signed-off-by: Dimitar Dimitrov <dimitar@dinux.eu>