gdb/testsuite: add build-id compile flag to tests that expect it

gdb/testsuite: add build-id compile flag to tests that expect it

Clang doesn't add build-id information by default, unlike gcc. This
means that tests that rely on build-id being available and don't
explicitly add it to the compilation options will fail with clang.
This commit fixes the fails in gdb.python/py-missing-debug.exp,
gdb.server/remote-read-msgs.exp, gdb.base/coredump-filter-build-id.exp
and gdb.server/solib-list.exp

Approved-By: Andrew Burgess <aburgess@redhat.com>