[dev.regabi] go/types: handle untyped constant arithmetic overflow

This is a port of CL 287832 for go/types. It differs from that CL in its
handling of position data. Unlike the syntax package, which has a
unified Operation node, go/types checks operations for ast.UnaryExpr,
IncDecStmt, and BinaryExpr. It was simpler to keep the existing position
logic. Notably, this correctly puts the errors on the operator.

Change-Id: Id1e3aefe863da225eb0a9b3628cfc8a5684c0c4f
Reviewed-on: https://go-review.googlesource.com/c/go/+/290569


Run-TryBot: Robert Findley <rfindley@google.com>
TryBot-Result: Go Bot <gobot@golang.org>
Reviewed-by: Robert Griesemer <gri@golang.org>
Trust: Robert Findley <rfindley@google.com>