scons: Add tag support to GdbXml.

Change-Id: I81c015fa8a5cc8f62aeb3f6cc409dc10fd3326e7
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/50328
Reviewed-by: Andreas Sandberg <andreas.sandberg@arm.com>
Maintainer: Gabe Black <gabe.black@gmail.com>
Tested-by: kokoro <noreply+kokoro@google.com>

src/SConscript

@@ -68,9 +68,9 @@ build_env = [(opt, env[opt]) for opt in export_vars]
 
 from code_formatter import code_formatter
 
-def GdbXml(xml_id, symbol):
+def GdbXml(xml_id, symbol, tags=None, add_tags=None):
     cc, hh = env.Blob(symbol, xml_id)
-    Source(cc)
+    Source(cc, tags=tags, add_tags=add_tags)
 
 class Source(SourceFile):
     pass