go/parser: resolve the type name when parsing a composite lit value

go/parser: resolve the type name when parsing a composite lit value

parsePrimaryExpr has to be careful to resolve identifiers used in
composite expressions when parsing in LHS mode. It missed the literal
type name.

Fixes #45136

Change-Id: I3e12f91e3ef5fdb43faa436cdf1240eb3293fe1a
Reviewed-on: https://go-review.googlesource.com/c/go/+/304451
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>