[lldb] Parse image high address from JSON crashlogs

[JDevlieghere]

Summary

Correctly parse the image high address from JSON crashlogs.

This is invisible in the output but necessary for a follow up patch that will test the new behavior.

[mib]

LGTM!

lldb/examples/python/crashlog.py

def parse_crash_reason(self, json_exception):
         return "{}{}{}".format(exception_type, exception_signal,
                                   exception_extra)
 
     def parse_images(self, json_images):
         idx = 0
         for json_image in json_images:
             img_uuid = uuid.UUID(json_image['uuid'])
             low = int(json_image['base'])
-            high = int(0)
+            high = low + int(
+                json_image['size']) if 'size' in json_image else low
             name = json_image['name'] if 'name' in json_image else ''
             path = json_image['path'] if 'path' in json_image else ''
             version = ''
             darwin_image = self.crashlog.DarwinImage(low, high, name, version,
                                                      img_uuid, path,
                                                      self.verbose)
             self.crashlog.images.append(darwin_image)
             idx += 1