Propagate subcut and dnwell up the hierarchy

sky130/magic/sky130.tech

diff --git a/sky130/magic/sky130.tech b/sky130/magic/sky130.tech
index 76e92f8..299f9e9 100644
--- a/sky130/magic/sky130.tech
+++ b/sky130/magic/sky130.tech
@@ -2460,10 +2460,17 @@
  variants *
  labels SUBPIN port
 
- layer dnwell DNWELL
+ templayer alldnwell DNWELL,lowerdnwell
+ copyup lowerdnwell
+
+ layer dnwell DNWELL,lowerdnwell
  labels DNWELL
 
- layer isosub SUBCUT
+ templayer alliso SUBCUT,loweriso
+ copyup loweriso
+
+ layer isosub SUBCUT,loweriso
+ and-not DNWELL,lowerdnwell
  labels SUBCUT
 
  layer npn DNWELL