Blacklist match_different_[member_]struct_names SSO validation tests.

Blacklist match_different_[member_]struct_names SSO validation tests.

This patch blacklists the following tests:

- dEQP-GLES31.functional.separate_shader.validation.varying.match_different_struct_names
- dEQP-GLES31.functional.separate_shader.validation.io_blocks.match_different_member_struct_names

The resolution of Khronos bug #15866 is that the spec should be changed
to require that "structures have the same name" in order for the types
to match during SSO validation.  These structures differ in name,
so they should not match, and we should get an SSO validation failure.

See https://cvs.khronos.org/bugzilla/show_bug.cgi?id=15866 and Khronos
legacy CTS commit 1607a3ce7caa5736471fb460d08130e62d689351.

Bug: 33457655