go/types: match Go 1.17 compiler error messages more closely
Introduce a new constant compilerErrorMessages, which is set to false
for now, so that we can port types2 error handling more precisely. Use
this to (partially) port CL 363436, excluding issue49005.go, which does
not exist in go/types (it was added in a previous CL related to compiler
error messages, that was not ported). I've also included the bugfix from
CL 364034, so that go/types is not broken at this commit.
In subsequent CLs I'll catch up with error handling locations in types2
that use compiler error messages.
Change-Id: I13fd6c43d61b28e0a7a3b0ae8ba785fb8506fbb7
Reviewed-on: https://go-review.googlesource.com/c/go/+/364379
Trust: Robert Findley <rfindley@google.com>
Run-TryBot: Robert Findley <rfindley@google.com>
TryBot-Result: Go Bot <gobot@golang.org> Reviewed-by: Robert Griesemer <gri@golang.org>