Some nptl tests inadvertently use the host's gdb to verify
libthread_db.so, which is loaded with the host's runtime. This causes
a couple of test failures when the host glibc does not support DT_RELR.
The not correct, but simple, workaround is to build without DT_RELR
as this library is otherwise likely to load on glibc 2.17 and newer
today.
This allows tst-pthread-gdb-attach{,-static} to continue working
when testing on a gdb loaded with an older glibc.
This avoids a failure in tst-pthread-gdb-attach similar to:
Trying host libthread_db library: .../build/glibc/nptl_db/libthread_db.so.1.
dlopen failed: /lib64/libc.so.6: version `GLIBC_ABI_DT_RELR' not found (required by .../build/glibc/nptl_db/libthread_db.so.1).
Reviewed-by: Carlos O'Donell <carlos@redhat.com>