This commit changes the `PartialComponentLinker` to use the original source
of an external template when compiling, if available, to ensure that the
source-mapping of the final linked code is accurate.
If the linker is given a file-system and logger, then it will attempt
to compute the original source of external templates so that the final
linked code references the correct template source.
PR Close#40237
This commit adds the basic building blocks for linking partial declarations.
In particular it provides a generic `FileLinker` class that delegates to
a set of (not yet implemented) `PartialLinker` classes.
The Babel plugin makes use of this `FileLinker` providing concrete classes
for `AstHost` and `AstFactory` that work with Babel AST. It can be created
with the following code:
```ts
const plugin = createEs2015LinkerPlugin({ /* options */ });
```
PR Close#39116
Pete Bacon Darwin