Even if a scope doesn't have variables, it may define a context
level different from enclosing scope. As debugger needs to know
context level at any point, bytecode generator should not elide
such scopes.
Change-Id: I2f97deae55285b758f91aee852338432dcddf373
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/109898
Reviewed-by: Régis Crelier <regis@google.com>
Reviewed-by: Ryan Macnak <rmacnak@google.com>
Commit-Queue: Alexander Markov <alexmarkov@google.com>