Previously, we had a special class,
ConstantEvaluationTarget_Annotation, for this purpose. It held on to
a the AST node for the annotation. This was bad because it meant that
the presence of any ConstantEvaluationTarget_Annotation referring to a
given compilation unit would keep the entire compilation unit's AST in
memory.
Now we copy just the portions of the AST we need into
ElementAnnotation, just as we do for all other constant evaluation
targets. In addition to saving memory, this paves the way for
supporting annotations in summaries, by making it possible to compute
the constant value of an annotation without having to consult the full
AST.
Fixes#25285.
R=brianwilkerson@google.com
Review URL: https://codereview.chromium.org/1665353002 .
Paul Berry
c43622e897