This fixes an issue where packages would be skipped if they contained
e.g. RxJS 5 style imports such as
```
import { observeOn } from 'rxjs/operators/observeOn';
```
Given that no package.json file can be found at the imported path, the
dependency would be reported missing, causing the package to be skipped.
PR Close #27031
Angular Compatibility Compiler (ngcc)
This compiler will convert node_modules compiled with ngc, into node_modules which
appear to have been compiled with ngtsc.
This conversion will allow such "legacy" packages to be used by the Ivy rendering engine.
Building
The project is built using Bazel:
yarn bazel build //packages/compiler-cli/src/ngcc
Unit Testing
The unit tests are built and run using Bazel:
yarn bazel test //packages/compiler-cli/src/ngcc/test
Integration Testing
There are tests that check the behaviour of the overall executable:
yarn bazel test //packages/compiler-cli/test/ngcc