This is needed as:
- closure declares globals itself for minified names, which sometimes clobber our `ng` global
- we can't declare a closure extern as the namespace `ng` is already used within Google for typings for angularJS (via `goog.provide('ng....')`).
With this commit `ngc` is used instead of `tsc-wrapped` for
collecting metadata and tsickle rewriting and `tsc-wrapped`
is removed from the repository.
`@angular/tsc-wrapped@5` is now deprecated and is no longer
used, updated, or maintained as part as of Angular 5.x.x.
`@angular/tsc-wrapped@4` is still maintained and required by
Angular 4.x.x and will be maintained as long as 4.x.x is in
LTS.
PR Close#19298
* Remove now unnecessary portions of build.
* Add a compilePackageES5 method to build ES5 from sources
* Rework all package.json and rollup config files to new format
* Remove "extends" from tsconfig-build.json files and fixup compilation roots
PR Close#18541