Previously the identifiers used in the typings files were the same as
those used in the source files.
When the typings files and the source files do not match exactly, e.g.
when one of them is flattened, while the other is a deep tree, it is
possible for identifiers to be renamed.
This commit ensures that the correct identifier is used in typings files
when the typings file does not export the same name as the source file.
Fixes https://github.com/angular/ngcc-validation/pull/608
PR Close#34254
31be29a9f3