[Rename] Allow renaming of symbols from another module

Retrieve the serialized location when checking rename availablity so
that global rename works on references outside the module it was
declared in.

Resolves rdar://94671287.

Author: bnbarham

lib/Refactoring/Refactoring.cpp

@@ -8811,7 +8811,7 @@ void swift::ide::collectRenameAvailabilityInfo(
     AvailKind = RenameAvailableKind::Unavailable_system_symbol;
   } else if (VD->getClangDecl()) {
     AvailKind = RenameAvailableKind::Unavailable_decl_from_clang;
-  } else if (VD->getStartLoc().isInvalid()) {
+  } else if (VD->getLoc().isInvalid()) {
     AvailKind = RenameAvailableKind::Unavailable_has_no_location;
   } else if (!VD->hasName()) {
     AvailKind = RenameAvailableKind::Unavailable_has_no_name;

test/SourceKit/Refactoring/rename-across-modules.swift

@@ -0,0 +1,18 @@
+// RUN: %empty-directory(%t)
+// RUN: %empty-directory(%t/build)
+// RUN: split-file --leading-lines %s %t
+
+// RUN: %target-swift-frontend -emit-module -module-name MyModule -emit-module-path %t/build/MyModule.swiftmodule -emit-module-source-info-path %t/build/MyModule.swiftsourceinfo %t/Action.swift
+
+//--- Action.swift
+public protocol Action {}
+
+//--- test.swift
+import MyModule
+
+// RUN: %sourcekitd-test -req=cursor -pos=%(line+1):19 -length=6 -cursor-action %t/test.swift -- %t/test.swift -I %t/build | %FileCheck %s
+func test(action: Action) { }
+// CHECK: ACTIONS BEGIN
+// CHECK-NEXT: source.refactoring.kind.rename.global
+// CHECK-NEXT: Global Rename
+// CHECK-NOT: cannot be renamed