cmd/compile: don't crash in size computation for invalid type
An invalid program may produce invalid types. If the program
calls unsafe.Sizeof on such a type, which is a compile-time
computation, the size-computation must be able to handle it.
Add the invalid type to the list of permissible basic types
and give it a size of 1 (word).
Fixes #52748.
Change-Id: I6c409628f9b77044758caf71cdcb199f9e77adea
Reviewed-on: https://go-review.googlesource.com/c/go/+/404894
Run-TryBot: Robert Griesemer <gri@google.com> Reviewed-by: Cuong Manh Le <cuong.manhle.vn@gmail.com> Reviewed-by: Robert Griesemer <gri@google.com>
Auto-Submit: Robert Griesemer <gri@google.com>
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