Revert "Disallow constructors of ES3 types in ES2 code."

This reverts commit 36f53ec7e10e16ad6c33156a5d5fa25975cc7fac.

Reason for revert: breaks DS3Types test

Original change's description:
> Disallow constructors of ES3 types in ES2 code.
>
> The fuzzer found that we constructed TypeReferences without first
> checking for disallowed tyoes. (In fact, TypeReference creation had no
> error checking at all; it didn't even have Convert/Make functions.)
>
> Added proper Convert/Make to TypeReference, and used those calls to
> report errors or cause assertions if trying to make a TypeReference to a
> type that the program did not support.
>
> (While tracking down this bug, I added strict-ES2 type assertions to our
> constructor IR nodes as well. This helped pinpoint the error and seem
> reasonable to leave in, just in case.)
>
> Change-Id: I896b68ae9d3d9e1f30d7eba9fa594617ab851c74
> Bug: oss-fuzz:39540
> Reviewed-on: https://skia-review.googlesource.com/c/skia/+/455498
> Commit-Queue: John Stiles <johnstiles@google.com>
> Commit-Queue: Brian Osman <brianosman@google.com>
> Auto-Submit: John Stiles <johnstiles@google.com>
> Reviewed-by: Brian Osman <brianosman@google.com>

Bug: oss-fuzz:39540
Change-Id: I1dc3ccca477fcb9fe3f39cfe8af1fd54dcb18d6b
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/455616
Auto-Submit: John Stiles <johnstiles@google.com>
Commit-Queue: Rubber Stamper <rubber-stamper@appspot.gserviceaccount.com>
Commit-Queue: John Stiles <johnstiles@google.com>
Bot-Commit: Rubber Stamper <rubber-stamper@appspot.gserviceaccount.com>
13 files changed