This brings Analyzer's type inference in line with the language spec.
Similar to CFE, the inference function now takes an isConst parameter,
which if set, tells it to eliminate type variables from the context
type.
Change-Id: Ied67bac39d73c9ecd7e0a482a0c8db77272637cc
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/98707
Reviewed-by: Paul Berry <paulberry@google.com>
Commit-Queue: Jenny Messerly <jmesserly@google.com>
Jenny Messerly