Revert "go/types, types2: remove unnecessary tests for x.typ == Typ[Invalid]"
This reverts commit
4c49d52439805c248f4a01d529b90b22e821b7d6.
Reason for revert: it is trickier than expected to enforce an invariant that x.typ == Typ[Invalid] => x.mode == invalid. For example, builtins have invalid type until their call is evaluated.
I think it is better to keep this defensive code for now. My bad for suggesting this strictness. I will send a follow-up CL with a test that exercises the panic discovered inside Google, and a bit more commentary about what 'invalid' means in both contexts.
Fixes #59603
Change-Id: If291f7268e7ef7ae6cd9bb861bb9af349a729cb2
Reviewed-on: https://go-review.googlesource.com/c/go/+/484375
TryBot-Result: Gopher Robot <gobot@golang.org>
Reviewed-by: Robert Griesemer <gri@google.com>
Run-TryBot: Robert Findley <rfindley@google.com>