cmd/compile: remove Node.Nincr, Node.Nelse, Node.Initplan

$ sizeof -p cmd/compile/internal/gc Node
Node 288
$

Change-Id: I4e316efa246132b3faa3a892e4fe9c9039250665
Reviewed-on: https://go-review.googlesource.com/10520
Reviewed-by: Ian Lance Taylor <iant@golang.org>
Reviewed-by: Josh Bleecher Snyder <josharian@gmail.com>
diff --git a/src/cmd/compile/internal/gc/walk.go b/src/cmd/compile/internal/gc/walk.go
index d5eb44c..5b3d585 100644
--- a/src/cmd/compile/internal/gc/walk.go
+++ b/src/cmd/compile/internal/gc/walk.go
@@ -255,13 +255,13 @@
 			addinit(&n.Ntest, init)
 		}
 
-		walkstmt(&n.Nincr)
+		walkstmt(&n.Right)
 		walkstmtlist(n.Nbody)
 
 	case OIF:
 		walkexpr(&n.Ntest, &n.Ninit)
 		walkstmtlist(n.Nbody)
-		walkstmtlist(n.Nelse)
+		walkstmtlist(n.Rlist)
 
 	case OPROC:
 		switch n.Left.Op {
@@ -3982,7 +3982,7 @@
 		return false
 	}
 
-	if !candiscard(n.Left) || !candiscard(n.Right) || !candiscard(n.Ntest) || !candiscard(n.Nincr) || !candiscardlist(n.Ninit) || !candiscardlist(n.Nbody) || !candiscardlist(n.Nelse) || !candiscardlist(n.List) || !candiscardlist(n.Rlist) {
+	if !candiscard(n.Left) || !candiscard(n.Right) || !candiscard(n.Ntest) || !candiscardlist(n.Ninit) || !candiscardlist(n.Nbody) || !candiscardlist(n.List) || !candiscardlist(n.Rlist) {
 		return false
 	}