This commit adds "find references" functionality to the Ivy integrated
language service. The basic approach is as follows:
1. Generate shims for all files to ensure we find references in shims
throughout the entire program
2. Determine if the position for the reference request is within a
template.
* Yes, it is in a template: Find which node in the template AST the
position refers to. Then find the position in the shim file for that
template node. Pass the shim file and position in the shim file along
to step 3.
* No, the request for references was made outside a template: Forward
the file and position to step 3.
3. (`getReferencesAtTypescriptPosition`): Call the native TypeScript LS
`getReferencesAtPosition`. For each reference that is in a shim file, map those
back to a template location, otherwise return it as-is.
PR Close#39768
In preparation for in-memory testing infrastructure, the existing Ivy
language service tests are moved to a `legacy` directory. These existing
tests rely on a single integration project in `test/project/app`, which
presents a number of challenges:
* adding extra fields/properties to the integration project for one test
can cause others to fail/flake.
* it's especially difficult to test any cases that require introducing
intentional errors, as those tend to break other tests.
* tests load files from disk, which is slower.
* tests rely on the real built versions of @angular/core and
@angular/common, which makes them both slow to build and require rebuilds
on every compiler change.
* tests share a single tsconfig.json, making it extremely difficult to test
how the language service handles different configuration scenarios (e.g.
different type-checking flags).
PR Close#39594
Andrew Scott
Alex Rickabaugh