Swift: add 5.7.1 migration scripts

Author: AlexDenisov

swift/downgrades/62fc609c1ab6ae748ff51362ffa5c368ba834ddf/implicit_conversion_exprs.ql

@@ -0,0 +1,8 @@
+// Removes AbiSafeConversionExprs from ImplicitConversionExprs
+class Element extends @element {
+  string toString() { none() }
+}
+
+from Element e, Element child
+where implicit_conversion_exprs(e, child) and not abi_safe_conversion_exprs(e)
+select e, child