Java: Add up/downgrade scripts

java/downgrades/1fd1afa7862b82955785edd29820054ab6c9ec81/erasure.ql

@@ -0,0 +1,9 @@
+class ClassOrInterface extends @classorinterface {
+  string toString() { none() }
+}
+
+from ClassOrInterface x, ClassOrInterface y
+where
+  classes_or_interfaces(x, _, _, y) and
+  x != y
+select x, y

java/downgrades/1fd1afa7862b82955785edd29820054ab6c9ec81/upgrade.properties

@@ -0,0 +1,3 @@
+description: Remove erasure
+compatibility: full
+erasure.rel: run erasure.qlo

java/ql/lib/upgrades/876cabc76c5c83912271db331481f8cba2749643/upgrade.properties

@@ -0,0 +1,2 @@
+description: Remove erasure
+erasure.rel: delete