[lldb] Fix racing issue when loading inlined symbols from crash report

Following abba5de, some tests started failing on green-dragon:

https://green.lab.llvm.org/green/job/lldb-cmake/55460/console

Looking at the backtrace, there seems to be a racing issue when deleting
the temporary directory containing all the JSON object files:

```
Traceback (most recent call last):
  File "/Users/buildslave/jenkins/workspace/lldb-cmake/lldb-build/lib/python3.10/site-packages/lldb/macosx/crashlog.py", line 1115, in __call__
    SymbolicateCrashLogs(debugger, shlex.split(command), result)
  File "/Users/buildslave/jenkins/workspace/lldb-cmake/lldb-build/lib/python3.10/site-packages/lldb/macosx/crashlog.py", line 1457, in SymbolicateCrashLogs
    SymbolicateCrashLog(crash_log, options)
  File "/Users/buildslave/jenkins/workspace/lldb-cmake/lldb-build/lib/python3.10/site-packages/lldb/macosx/crashlog.py", line 1158, in SymbolicateCrashLog
    with tempfile.TemporaryDirectory() as obj_dir:
  File "/usr/local/opt/[email protected]/Frameworks/Python.framework/Versions/3.10/lib/python3.10/tempfile.py", line 869, in __exit__
    self.cleanup()
  File "/usr/local/opt/[email protected]/Frameworks/Python.framework/Versions/3.10/lib/python3.10/tempfile.py", line 873, in cleanup
    self._rmtree(self.name, ignore_errors=self._ignore_cleanup_errors)
  File "/usr/local/opt/[email protected]/Frameworks/Python.framework/Versions/3.10/lib/python3.10/tempfile.py", line 855, in _rmtree
    _shutil.rmtree(name, onerror=onerror)
  File "/usr/local/opt/[email protected]/Frameworks/Python.framework/Versions/3.10/lib/python3.10/shutil.py", line 731, in rmtree
    onerror(os.rmdir, path, sys.exc_info())
  File "/usr/local/opt/[email protected]/Frameworks/Python.framework/Versions/3.10/lib/python3.10/shutil.py", line 729, in rmtree
    os.rmdir(path)
OSError: [Errno 66] Directory not empty: '/var/folders/09/r4vw4v8n5kb67jl66zvlbljw0000gn/T/tmp6qfifxk7'
```

This patch should fix that issue since it won't delete the object file
directory until we're sure that the modules adding tasks completed.

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

Author: medismailben

lldb/examples/python/crashlog.py

@@ -1154,8 +1154,8 @@ def SymbolicateCrashLog(crash_log, options):
 
     futures = []
     loaded_images = []
-    with concurrent.futures.ThreadPoolExecutor() as executor:
-        with tempfile.TemporaryDirectory() as obj_dir:
+    with tempfile.TemporaryDirectory() as obj_dir:
+        with concurrent.futures.ThreadPoolExecutor() as executor:
 
             def add_module(image, target, obj_dir):
                 return image, image.add_module(target, obj_dir)
@@ -1166,12 +1166,12 @@ def add_module(image, target, obj_dir):
                         add_module, image=image, target=target, obj_dir=obj_dir
                     )
                 )
-        for future in concurrent.futures.as_completed(futures):
-            image, err = future.result()
-            if err:
-                print(err)
-            else:
-                loaded_images.append(image)
+            for future in concurrent.futures.as_completed(futures):
+                image, err = future.result()
+                if err:
+                    print(err)
+                else:
+                    loaded_images.append(image)
 
     if crash_log.backtraces:
         for thread in crash_log.backtraces: