[dev.typeparams] Don't check typecheck(3) on transform, so no need to export/import it
We have a value typecheck(3) that indicates that a node in a generic
function still needs transformation (via the functions in transform.go).
But it is not very desirable to export/import the value of typecheck(3).
So, I changed the stenciling code to just try to transform all relevant
node types during node copy. Almost all tranform functions were already
idempotent. I only had to add an extra if check before calling
transformAssign() in the OAS case. We still use the typecheck(3) in
noder to determine when higher-nodes have to delay transformation
because one or more of their args are delaying transformation.
Added new test mapsimp.go that required these tranformations after import.
As an additional change, export/import of OINDEX requires exporting the
type using w.exoticType() rather than w.typ(), in order to handle
generic functions. Since generic functions can have pre-transform
operations, the index operation can have a tuple type (multiple return
from a map lookup).
Added printing of imported function bodies in -W=3 debug mode.
Change-Id: I220e2428dc5f2741e91db146f075eb5b6045f451
Reviewed-on: https://go-review.googlesource.com/c/go/+/322191
Trust: Dan Scales <danscales@google.com>
Run-TryBot: Dan Scales <danscales@google.com> Reviewed-by: Keith Randall <khr@golang.org>
TryBot-Result: Go Bot <gobot@golang.org>