cmd/compile: fix maplit init panics for dynamic entry

cmd/compile: fix maplit init panics for dynamic entry

golang.org/cl/174498 removes dynamic map entry handling in maplit, by
filtering the static entry only. It panics if it see a dynamic entry.
It relies on order to remove all dynamic entries.

But after recursively call order on the statics, some static entries
become dynamic, e.g OCONVIFACE node:

	type i interface {
		j()
	}
	type s struct{}

	func (s) j() {}

	type foo map[string]i

	var f = foo{
		"1": s{},
	}

To fix it, we recursively call order on each static entry, if it changed
to dynamic, put entry to dynamic then.

Fixes #31777

Change-Id: I1004190ac8f2d1eaa4beb6beab989db74099b025
Reviewed-on: https://go-review.googlesource.com/c/go/+/174777
Run-TryBot: Matthew Dempsky <mdempsky@google.com>
Reviewed-by: Keith Randall <khr@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>