While evaluating a class literal the containing function points to
Token::CLASS. It may have pushed a context for that class that uses
the range of the class scope. So far the class scope had a range that
started after the class name or class token in case of anonymous
classes. That means the source position of the function frame doesn't
point to a position that is included in the active context range. This
breaks the debugger because it relies on being able to find the
matching parser scope for the active context by looking at the source
position.

The fix is two-fold:
- extend the class scope source range to include Token::CLASS
- update ScopeChainRetriever::ContainsPosition to include the start
  position of class scopes as a valid source position. We can't always
  include start due to arrow functions that don't have braces.

Bug: chromium:1156498
Change-Id: I9ec640c6326289dadcb154bb0a329ca6f8188f8b
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2857957Reviewed-by: Leszek Swirski <leszeks@chromium.org>
Commit-Queue: Leszek Swirski <leszeks@chromium.org>
Auto-Submit: Toon Verwaest <verwaest@chromium.org>
Cr-Commit-Position: refs/heads/master@{#74268}