cmd/compile/internal/syntax: more strict parsing of type instances
Report a syntax error if the first element of a type instance is
not actually a type (but some other expression), rather then relying
on the type checker error in this case. This matches the behavior of
go/parser. Adjust the corresponding types2 test case.
For #54511.
Change-Id: Ia82b3a7d444738c56955ce6c15609470b3431fd1
Reviewed-on: https://go-review.googlesource.com/c/go/+/426657 Reviewed-by: Robert Griesemer <gri@google.com>
Auto-Submit: Robert Griesemer <gri@google.com>
Run-TryBot: Robert Griesemer <gri@google.com> Reviewed-by: Robert Findley <rfindley@google.com>
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