This commit fixes a bug introduced in the recent refactoring whereby
caches become stale when the program changes.
This is because StaticReflector keeps its own caches that are not
clearable. The previous refactoring tried to reuse the same instance,
leading to out-of-sync program state.
Clearing out the *entire* cache is very inefficient. Instead, we could
just invalidate the symbols in the files that have changed. This
requires changes to the API of StaticReflector, but put this on hold
until the refactoring of language service for Ivy commences.
PR closes https://github.com/angular/angular/issues/32301
PR Close#32357