[migrator] Filter out diag::wrong_argument_labels for the fixit pass

The migrator only applies changes from the APIDiffMigratorPass in the primary
file. This means that if a nominal type was renamed, for example, any members
users have added in an extension in a separate file won't be visible, because
the extension would still have the old name. This can result in 'wrong argument
label' errors with fixits to change the argument labels that, when applied by
the fixit pass, completely change which function was being called and cause
post-migration errors.

This patch updates the fixit pass to ignore diag::wrong_argument_labels.
diag::extra_argument_labels and diag::missing_argument_labels were already
filtered out for other reasons.

Resolves rdar://problem/40170377

include/swift/Migrator/FixitFilter.h

@@ -61,6 +61,18 @@ struct FixitFilter {
         Info.ID == diag::invalid_ibinspectable.ID ||
         Info.ID == diag::invalid_ibaction_decl.ID)
       return false;
+
+    // The Migrator only applies changes from the APIDiffMigratorPass in the
+    // primary file, so if a nominal type was renamed, for example, any members
+    // users have added in an extension in a separate file may not be visible,
+    // due to the extension rename not having been applied. The below diag(s)
+    // can provide undesireable fixits that rename references of these
+    // no-longer-visible members to similar still-visible ones.
+    // Note: missing_argument_lables and extra_argument_labels are filtered out
+    // elsewhere
+    if (Info.ID == diag::wrong_argument_labels.ID)
+      return false;
+
     // Adding type(of:) interacts poorly with the swift migrator by
     // invalidating some inits with type errors.
     if (Info.ID == diag::init_not_instance_member.ID)

test/Migrator/Inputs/API.json

@@ -528,5 +528,16 @@
     "RightUsr": "",
     "RightComment": "Int",
     "ModuleName": "Cities"
+  },
+  {
+    "DiffItemKind": "CommonDiffItem",
+    "NodeKind": "TypeDecl",
+    "NodeAnnotation": "Rename",
+    "ChildIndex": "0",
+    "LeftUsr": "s:6Cities10FontWeightO",
+    "LeftComment": "FontWeight",
+    "RightUsr": "",
+    "RightComment": "FontWeighting",
+    "ModuleName": "Cities"
   }
 ]

test/Migrator/Inputs/Cities.swift

@@ -62,3 +62,15 @@ open class ToplevelType {
 }
 
 public var GlobalAttribute: String = ""
+
+public enum FontWeighting: Int {
+  case Light = 0
+  case Regular
+  case Bold
+}
+
+public enum FontWeight: Int {
+  case Light = 0
+  case Regular
+  case Bold
+}

test/Migrator/Inputs/rename_cross_file_2.swift

@@ -0,0 +1,7 @@
+import Cities
+
+extension FontWeight {
+  init(string: String) { fatalError() }
+  init(x: Int, y: Int, z: Int) { fatalError() }
+  init(x: Int, _ y: Int) { fatalError() }
+}

test/Migrator/rename_cross_file.swift

@@ -0,0 +1,18 @@
+// REQUIRES: objc_interop
+// RUN: %empty-directory(%t.mod) && %target-swift-frontend -emit-module -o %t.mod/Cities.swiftmodule %S/Inputs/Cities.swift -module-name Cities -parse-as-library
+// RUN: %empty-directory(%t) && %target-swift-frontend -c -update-code -primary-file %s %S/Inputs/rename_cross_file_2.swift -F %S/mock-sdk -I %t.mod -api-diff-data-file %S/Inputs/API.json -emit-migrated-file-path %t/rename_cross_file.swift.result -emit-remap-file-path %t/rename_cross_file.swift.remap -o /dev/null
+// RUN: diff -u %S/rename_cross_file.swift.expected %t/rename_cross_file.swift.result
+
+import Cities
+
+extension FontWeight {
+  init(x: Int, y: Int) { fatalError() }
+  init(x: Int, y: Int, _ z: Int) { fatalError() }
+}
+
+func foo() {
+  _ = FontWeight(rawValue: 1)
+  _ = FontWeight(string: "light")
+  _ = FontWeight(x: 2, y: 2, z: 2)
+  _ = FontWeight(x: 2, 2)
+}

test/Migrator/rename_cross_file.swift.expected

@@ -0,0 +1,18 @@
+// REQUIRES: objc_interop
+// RUN: %empty-directory(%t.mod) && %target-swift-frontend -emit-module -o %t.mod/Cities.swiftmodule %S/Inputs/Cities.swift -module-name Cities -parse-as-library
+// RUN: %empty-directory(%t) && %target-swift-frontend -c -update-code -primary-file %s %S/Inputs/rename_cross_file_2.swift -F %S/mock-sdk -I %t.mod -api-diff-data-file %S/Inputs/API.json -emit-migrated-file-path %t/rename_cross_file.swift.result -emit-remap-file-path %t/rename_cross_file.swift.remap -o /dev/null
+// RUN: diff -u %S/rename_cross_file.swift.expected %t/rename_cross_file.swift.result
+
+import Cities
+
+extension FontWeighting {
+  init(x: Int, y: Int) { fatalError() }
+  init(x: Int, y: Int, _ z: Int) { fatalError() }
+}
+
+func foo() {
+  _ = FontWeighting(rawValue: 1)
+  _ = FontWeighting(string: "light")
+  _ = FontWeighting(x: 2, y: 2, z: 2)
+  _ = FontWeighting(x: 2, 2)
+}