Swift: add 5.7.1 migration scripts

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

swift/downgrades/62fc609c1ab6ae748ff51362ffa5c368ba834ddf/unspecified_elements.ql

@@ -0,0 +1,13 @@
+// Moves AbiSafeConversionExprs into UnspecifiedElements
+class Element extends @element {
+  string toString() { none() }
+}
+
+from Element e, string property, string error
+where
+  abi_safe_conversion_exprs(e) and
+  property = "" and
+  error = "Removed ABISafeConversionExpr during the database downgrade"
+  or
+  unspecified_elements(e, property, error)
+select e, property, error

swift/downgrades/62fc609c1ab6ae748ff51362ffa5c368ba834ddf/upgrade.properties

@@ -0,0 +1,5 @@
+description: Remove new implicit conversion
+compatibility: partial
+unspecified_elements.rel: run unspecified_elements.ql
+implicit_conversion_exprs.rel: run implicit_conversion_exprs.ql
+abi_safe_conversion_exprs.rel: delete

swift/ql/lib/upgrades/1a6e9325bd60462e669e524438174deef4476df0/upgrade.properties

@@ -0,0 +1,2 @@
+description: Added new implicit conversion
+compatibility: full