[lldb/crashlog] Make image loading in tests single-threaded

This patch has a temporary fix for a non-deterministic deadlock when
loading crashlog images in parallel, by making it single-threaded.

Also given that dSYMForUUID is disabled on the CI (following f8afa76),
this shouldn't cause any noticeable slowdown while running the test suite.

Signed-off-by: Med Ismail Bennani <[email protected]>

Author: medismailben

lldb/examples/python/crashlog.py

@@ -1814,6 +1814,9 @@ def SymbolicateCrashLogs(debugger, command_args, result, is_command):
             )
         )
 
+    if "NO_PARALLEL_IMG_LOADING" in os.environ:
+        options.no_parallel_image_loading = True
+
     if options.version:
         print(debugger.GetVersionString())
         return

lldb/test/Shell/ScriptInterpreter/Python/Crashlog/lit.local.cfg

@@ -5,3 +5,6 @@ if 'lldb-repro' in config.available_features:
   config.unsupported = True
 
 config.environment["LLDB_APPLE_DSYMFORUUID_EXECUTABLE"] = ""
+
+# Temporary parallel image loading deadlock workaround
+config.environment["NO_PARALLEL_IMG_LOADING"] = ""