Generated factory shims can import from @angular/core. However, we have
special logic in place to rewrite self-imports when generating code for
@angular/core.
This commit leverages the new standalone ImportRewriter interface to
properly rewrite imports in generated factory shims. Before this fix,
a generated factory file for core would look like:
```typescript
import * as i0 from './r3_symbols';
export var ApplicationModuleNgFactory = new ɵNgModuleFactory(...);
```
This is invalid, as ɵNgModuleFactory is just NgModuleFactory when imported
via r3_symbols.
FW-881 #resolve
PR Close#27998
This refactoring moves code around between a few of the ngtsc subpackages,
with the goal of having a more logical package structure. Additional
interfaces are also introduced where they make sense.
The 'metadata' package formerly contained both the partial evaluator,
the TypeScriptReflectionHost as well as some other reflection functions,
and the Reference interface and various implementations. This package
was split into 3 parts.
The partial evaluator now has its own package 'partial_evaluator', and
exists behind an interface PartialEvaluator instead of a top-level
function. In the future this will be useful for reducing churn as the
partial evaluator becomes more complicated.
The TypeScriptReflectionHost and other miscellaneous functions have moved
into a new 'reflection' package. The former 'host' package which contained
the ReflectionHost interface and associated types was also merged into this
new 'reflection' package.
Finally, the Reference APIs were moved to the 'imports' package, which will
consolidate all import-related logic in ngtsc.
PR Close#27743
This simple refactor of the build rules renames the .ngfactory.js shim
generator to 'shims' instead of 'factories', in preparation for adding
.ngsummary.js shim generation.
Testing strategy: this commit does not introduce any new behavior and
merely moves files and symbols around. It's sufficient that the existing
ngtsc tests pass.
PR Close#26495
