[cross-project-tests] Use "is" instead of "==" to check for None (#94016)

From PEP8
(https://peps.python.org/pep-0008/#programming-recommendations):

> Comparisons to singletons like None should always be done with is or
is not, never the equality operators.

cross-project-tests/debuginfo-tests/dexter/dex/command/ParseCommand.py

@@ -98,7 +98,7 @@ def _build_command(
 
     def label_to_line(label_name: str) -> int:
         line = labels.get(label_name, None)
-        if line != None:
+        if line is not None:
             return line
         raise format_unresolved_label_err(label_name, raw_text, path.base, lineno)
 

cross-project-tests/debuginfo-tests/dexter/dex/debugger/DebuggerControllers/ConditionalController.py

@@ -62,7 +62,7 @@ class BreakpointRange:
         self.finish_on_remove = finish_on_remove
 
     def has_conditions(self):
-        return self.expression != None
+        return self.expression is not None
 
     def get_conditional_expression_list(self):
         conditional_list = []
@@ -76,7 +76,7 @@ class BreakpointRange:
         self.current_hit_count += 1
 
     def should_be_removed(self):
-        if self.max_hit_count == None:
+        if self.max_hit_count is None:
             return False
         return self.current_hit_count >= self.max_hit_count
 

cross-project-tests/debuginfo-tests/dexter/dex/debugger/DebuggerControllers/ControllerHelpers.py

@@ -39,7 +39,7 @@ def update_step_watches(step_info, watches, commands):
         for watch in towatch:
             loc = step_info.current_location
             if (
-                loc.path != None
+                loc.path is not None
                 and os.path.exists(loc.path)
                 and os.path.samefile(watch.path, loc.path)
                 and have_hit_line(watch, loc)

cross-project-tests/debuginfo-tests/dexter/dex/debugger/Debuggers.py

@@ -183,7 +183,7 @@ def handle_debugger_tool_options(context, defaults):  # noqa
         if options.debugger == "lldb":
             _warn_meaningless_option(context, "--show-debugger")
 
-    if options.source_root_dir != None:
+    if options.source_root_dir is not None:
         if not os.path.isabs(options.source_root_dir):
             raise ToolArgumentError(
                 f'<d>--source-root-dir: expected absolute path, got</> <r>"{options.source_root_dir}"</>'

cross-project-tests/debuginfo-tests/dexter/dex/debugger/visualstudio/VisualStudio.py

@@ -256,7 +256,7 @@ class VisualStudio(
         for bp in self._debugger.Breakpoints:
             # We're looking at the user-set breakpoints so there should be no
             # Parent.
-            assert bp.Parent == None
+            assert bp.Parent is None
             this_vsbp = VSBreakpoint(
                 PurePath(bp.File), bp.FileLine, bp.FileColumn, bp.Condition
             )

cross-project-tests/debuginfo-tests/dexter/dex/tools/test/Tool.py

@@ -150,7 +150,7 @@ class Tool(TestToolBase):
         """Returns the path to the test results directory for the test denoted
         by test_name.
         """
-        assert self.context.options.results_directory != None
+        assert self.context.options.results_directory is not None
         return os.path.join(
             self.context.options.results_directory,
             self._get_results_basename(test_name),

cross-project-tests/lit.cfg.py

@@ -51,7 +51,7 @@ tools = [
 
 def get_required_attr(config, attr_name):
     attr_value = getattr(config, attr_name, None)
-    if attr_value == None:
+    if attr_value is None:
         lit_config.fatal(
             "No attribute %r in test configuration! You may need to run "
             "tests from your build directory or add this attribute "