All errors for existing fields have been detected and suppressed with a
`!` assertion.
Issue/24571 is tracking proper clean up of those instances.
One-line change required in ivy/compilation.ts, because it appears that
the new syntax causes tsickle emitted node to no longer track their
original sourceFiles.
PR Close#24572
Closure compiler with type based optimizations has a bug where externs for inherited static fields are not being honored. For Angular Elements this meant that 'observedAttributes' static field which is marked as an extern for the base HTMLElement class was getting renamed.
This commit works around the bug by using quoted access of 'observedAttributes' that explicitly prevents the renaming.
PR Close#23843
