cmd/compile: make unified IR more selective about method wrappers
This CL makes two changes to how unified IR emits method wrappers:
1. It no longer emits wrappers for defined types' underlying
types. Previously, a declaration like `type T struct { U }` would emit
wrappers for both `T` and `struct { U }`. Now they're only emitted for
`T`.
2. It emits method value wrappers only when OMETHVALUE nodes are
actually created, like how -G=0 works. Method values are relatively
rare, aren't needed for runtime type descriptors (unlike method
expression wrappers), and large projects end up spending a non-trivial
amount of time compiling these unneeded wrappers.
Change-Id: I21da97df3132ec12cc67debf62b5b2d282f481cf
Reviewed-on: https://go-review.googlesource.com/c/go/+/346230
Trust: Matthew Dempsky <mdempsky@google.com>
Run-TryBot: Matthew Dempsky <mdempsky@google.com>
TryBot-Result: Go Bot <gobot@golang.org> Reviewed-by: Cuong Manh Le <cuong.manhle.vn@gmail.com>