reloc: provide libthread_db.so.1 to debug thread on gdb

In scylla-debuginfo package, we have /usr/lib/debug/opt/scylladb/libreloc/libthread_db-1.0.so-666.development-0.20190711.73a1978fb.el7.x86_64.debug
but we actually does not have libthread_db.so.1 in /opt/scylladb/libreloc
since it's not available on ldd result with scylla binary.

To debug thread, we need to add the library in a relocatable package manually.

Fixes #4673

Signed-off-by: Takuya ASADA <syuu@scylladb.com>
Message-Id: <20190711111058.7454-1-syuu@scylladb.com>

scripts/create-relocatable-package.py

@@ -76,6 +76,9 @@ def ldd(executable):
 for exe in executables:
     libs.update(ldd(exe))
 
+# manually add libthread_db for debugging thread
+libs.update({'libthread_db-1.0.so': '/lib64/libthread_db-1.0.so'})
+
 ld_so = libs['ld.so']
 
 have_gnutls = any([lib.startswith('libgnutls.so')