[dev.regabi] cmd/compile: remove gc ↔ ssa cycle hacks

The cycle hacks existed because gc needed to import ssa
which need to know about gc.Node. But now that's ir.Node,
and there's no cycle anymore.

Don't know how much it matters but LocalSlot is now
one word shorter than before, because it holds a pointer
instead of an interface for the *Node. That won't last long.

Now that they're not necessary for interface satisfaction,
IsSynthetic and IsAutoTmp can move to top-level ir functions.

Change-Id: Ie511e93466cfa2b17d9a91afc4bd8d53fdb80453
Reviewed-on: https://go-review.googlesource.com/c/go/+/272931
Trust: Russ Cox <rsc@golang.org>
Run-TryBot: Russ Cox <rsc@golang.org>
TryBot-Result: Go Bot <gobot@golang.org>
Reviewed-by: Matthew Dempsky <mdempsky@google.com>

1 files changed, 5 insertions, 27 deletions

diff --git a/src/cmd/compile/internal/ssa/export_test.go b/src/cmd/compile/internal/ssa/export_test.go
index bfe94ff160..3d142a2272 100644
--- a/src/cmd/compile/internal/ssa/export_test.go
+++ b/src/cmd/compile/internal/ssa/export_test.go
@@ -5,6 +5,7 @@
 package ssa
 
 import (
+	"cmd/compile/internal/ir"
 	"cmd/compile/internal/types"
 	"cmd/internal/obj"
 	"cmd/internal/obj/arm64"
@@ -65,36 +66,13 @@ type TestFrontend struct {
 	ctxt *obj.Link
 }
 
-type TestAuto struct {
-	t *types.Type
-	s string
-}
-
-func (d *TestAuto) Typ() *types.Type {
-	return d.t
-}
-
-func (d *TestAuto) String() string {
-	return d.s
-}
-
-func (d *TestAuto) StorageClass() StorageClass {
-	return ClassAuto
-}
-
-func (d *TestAuto) IsSynthetic() bool {
-	return false
-}
-
-func (d *TestAuto) IsAutoTmp() bool {
-	return true
-}
-
 func (TestFrontend) StringData(s string) *obj.LSym {
 	return nil
 }
-func (TestFrontend) Auto(pos src.XPos, t *types.Type) GCNode {
-	return &TestAuto{t: t, s: "aTestAuto"}
+func (TestFrontend) Auto(pos src.XPos, t *types.Type) *ir.Node {
+	n := ir.NewNameAt(pos, &types.Sym{Name: "aFakeAuto"})
+	n.SetClass(ir.PAUTO)
+	return n
 }
 func (d TestFrontend) SplitString(s LocalSlot) (LocalSlot, LocalSlot) {
 	return LocalSlot{N: s.N, Type: testTypes.BytePtr, Off: s.Off}, LocalSlot{N: s.N, Type: testTypes.Int, Off: s.Off + 8}