Changes the logic for parsing analyzer-style `messages.yaml` files so
that an optional `type:` entry is accepted. When present, the type
will be checked against the type inferred from the diagnostic code's
class (`CompileTimeErrorCode` has type `compileTimeError`,
`StaticWarningCode` has type `staticWarning`, etc).
In a follow-up CL I will add these `type:` entries, and change the
code generation logic to use them instead of inferring the type from
the diagnostic code's class. This will pave the way for removing the
notion of diagnostic code class entirely.
Change-Id: I6a6a6964d58f06ea6573702f9afcc61b5370eda8
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/464242
Reviewed-by: Konstantin Shcheglov <scheglov@google.com>
Paul Berry
5f569bf333