cmd/compile: remove nodesOrNodeListPtr outside of syntax.go

Passes toolstash -cmp.

Update #14473.

Change-Id: I2620374b79c61b1e48467b98afe2d7d3beef878b
Reviewed-on: https://go-review.googlesource.com/20354
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
diff --git a/src/cmd/compile/internal/gc/swt.go b/src/cmd/compile/internal/gc/swt.go
index 137be94..d6b7c2c 100644
--- a/src/cmd/compile/internal/gc/swt.go
+++ b/src/cmd/compile/internal/gc/swt.go
@@ -279,7 +279,7 @@
 	if nerrors == 0 {
 		cas = append(cas, def)
 		sw.Nbody.Set(append(cas, sw.Nbody.Slice()...))
-		walkstmtlist(sw.Nbody)
+		walkstmtlist(sw.Nbody.Slice())
 	}
 }
 
@@ -670,7 +670,7 @@
 		cas = append(cas, def)
 		sw.Nbody.Set(append(cas, sw.Nbody.Slice()...))
 		setNodeSeq(&sw.List, nil)
-		walkstmtlist(sw.Nbody)
+		walkstmtlist(sw.Nbody.Slice())
 	}
 }