[FixCode] Disable a migrating fixit that interacts badly with the migrator.

For such code:
  func test(p: Int, _: String) {}
  test(0, "")

the compiler bizarrely suggests to change order of arguments in the call site.

Author: akyrtzi

lib/FrontendTool/FrontendTool.cpp

@@ -598,6 +598,13 @@ class JSONFixitWriter : public DiagnosticConsumer {
     if (Info.ID == diag::objc_witness_selector_mismatch.ID ||
         Info.ID == diag::witness_non_objc.ID)
       return false;
+    // This interacts badly with the migrator. For such code:
+    //   func test(p: Int, _: String) {}
+    //   test(0, "")
+    // the compiler bizarrely suggests to change order of arguments in the call
+    // site.
+    if (Info.ID == diag::argument_out_of_order_unnamed_unnamed.ID)
+      return false;
     // The following interact badly with the swift migrator by removing @IB*
     // attributes when there is some unrelated type issue.
     if (Info.ID == diag::invalid_iboutlet.ID ||

test/FixCode/fixits-apply.swift

@@ -254,3 +254,6 @@ func testProtocolCompositionSyntax() {
   var _: protocol<Prot1>
   var _: protocol<Prot1, Prot2>
 }
+
+func disable_unnamed_param_reorder(p: Int, _: String) {}
+disable_unnamed_param_reorder(0, "") // no change.

test/FixCode/fixits-apply.swift.result

@@ -257,3 +257,6 @@ func testProtocolCompositionSyntax() {
   var _: Prot1
   var _: Prot1 & Prot2
 }
+
+func disable_unnamed_param_reorder(p: Int, _: String) {}
+disable_unnamed_param_reorder(0, "") // no change.