[dev.typeparams] cmd/compile: allow conversions from type parameter to interface
When converting from a type param to an interface, allow it if
the type bound implements that interface.
Query: some conversions go through this path, some use another path?
The test does
var i interface{foo()int} = x
but
i := (interface{foo()int})(x)
works at tip.
Change-Id: I84d497e5228c0e1d1c9d76ffebaedce09dc45e8e
Reviewed-on: https://go-review.googlesource.com/c/go/+/325409
Trust: Keith Randall <khr@golang.org>
Trust: Dan Scales <danscales@google.com>
Run-TryBot: Keith Randall <khr@golang.org>
TryBot-Result: Go Bot <gobot@golang.org> Reviewed-by: Dan Scales <danscales@google.com>