Rewrite Tsickle to use TypeScript v2.1 transforms

[mhevery]

Currently Tsickle does not use TypeScript v2.1 transforms API. The consequence is that ngc has to parse the type information twice. Once for the original source code, and then again when tsickle pulls annotations into static fields. The consequence of this is slower runtime performance.

[mhevery]

/cc @chuckjaz

[evmar]

Did they expose the transforms API to external users? Last I heard this was an internal-only API.

[mhevery]

My understanding from discussing with @chuckjaz is that it will be available in v2.1.

[mprobst]

@chuckjaz do you have a pointer to docs on it?

[evmar]

I just checked the TS source and the transforms stuff is still marked @internal.

https://github.com/Microsoft/TypeScript/blob/012159b25db2b0aa77690d984ee4c35bd7ef2b56/src/compiler/transformer.ts#L14

[evmar]

Depends on #295 first.

[evmar]

Last news on this is that they anticipate exposing transforms in the next few weeks, but it'll be in a later TS release. We can wait.

[shlomiassaf]

Seems like 1 more thing left for this transformer API.

See this comment

[KiaraGrouwstra]

As I understand it their alternative PR for this has been merged by now. Hope that could unblock this for those AoT lambdas! @chuckjaz @mhevery

[evmar]

We need to migrate tsickle to TS 2.3 for this new API. Historically that's taken a small amount of work to adjust to API changes but I haven't looked yet at how hard it will be.

[KiaraGrouwstra]

With the TS upgrade down (#471) I guess this is unblocked now.

[evmar]

Fixed.