[test] Deprecate test data download for most test suites

tools/run-tests.py

Index: tools/run-tests.py
diff --git a/tools/run-tests.py b/tools/run-tests.py
index 2fdbd9d89e811966d3b8bb4976f6a7e2a335955b..e982cdc5050bfbc808ac58374775dcfdd7c5f706 100755
--- a/tools/run-tests.py
+++ b/tools/run-tests.py
@@ -252,7 +252,7 @@ def BuildOptions():
   result.add_option("--download-data", help="Download missing test suite data",
                     default=False, action="store_true")
   result.add_option("--download-data-only",
-                    help="Download missing test suite data and exit",
+                    help="Deprecated",
                     default=False, action="store_true")
   result.add_option("--extra-flags",
                     help="Additional flags to pass to each test command",
@@ -667,6 +667,9 @@ def Main():
   if options.download_data_only:
     return exit_code
 
+  for s in suites:
+    s.PrepareSources()
+
   for (arch, mode) in options.arch_and_mode:
     try:
       code = Execute(arch, mode, args, options, suites)