cmd/compile: change ir.InstExpr.Targs from Node to Ntype
Type arguments are always type expressions, which are semantically
represented by Ntype.
In fact, the slice should probably just be []*types.Type instead, and
that would remove a lot of ir.TypeNode wrapping/unwrapping. But this
lead to issues within the stenciling code, and I can't immediately
make sense why.
Change-Id: Ib944db30e4d21284bc2d8d954b68ecb70b4205a9
Reviewed-on: https://go-review.googlesource.com/c/go/+/403843 Reviewed-by: David Chase <drchase@google.com>
TryBot-Result: Gopher Robot <gobot@golang.org> Reviewed-by: Cuong Manh Le <cuong.manhle.vn@gmail.com>
Run-TryBot: Matthew Dempsky <mdempsky@google.com>