[ClangImporter] Add tests for generic compatibility typealiases.

The implementation here is pretty slapdash, and I'm about to do
something safer, but it seems to be working now and I don't want
to break it.

Author: jrose-apple

test/APINotes/Inputs/custom-frameworks/APINotesFrameworkTest.framework/Headers/APINotesFrameworkTest.apinotes

@@ -86,6 +86,8 @@ SwiftVersions:
             SwiftImportAsAccessors: true
       - Name: NewlyGenericSub
         SwiftImportAsNonGeneric: true
+      - Name: RenamedGeneric
+        SwiftName: OldRenamedGeneric
     Protocols:
       - Name: ProtoWithVersionedUnavailableMember
         Methods:

test/APINotes/Inputs/custom-frameworks/APINotesFrameworkTest.framework/Headers/Classes.h

@@ -5,5 +5,8 @@
 + (Element)defaultElement;
 @end
 
+@interface RenamedGeneric<Element: Base *> : Base
+@end
+
 #pragma clang assume_nonnull end
 #endif // __OBJC__

test/APINotes/versioned-objc.swift

@@ -23,4 +23,24 @@ func testNonGeneric() {
   // CHECK-DIAGS-4:[[@LINE-1]]:{{[0-9]+}}: error: cannot convert value of type 'Base' to specified type 'Int'
 }
 
+func testRenamedGeneric() {
+  // CHECK-DIAGS-3:[[@LINE+1]]:{{[0-9]+}}: error: 'RenamedGeneric' has been renamed to 'OldRenamedGeneric'
+  let _: OldRenamedGeneric<Base> = RenamedGeneric<Base>()
+  // FIXME-DIAGS-4:[[@LINE-1]]:{{[0-9]+}}: error: 'OldRenamedGeneric' has been renamed to 'RenamedGeneric'
+
+  // FIXME-DIAGS-3:[[@LINE+1]]:{{[0-9]+}}: error: 'RenamedGeneric' has been renamed to 'OldRenamedGeneric'
+  let _: RenamedGeneric<Base> = OldRenamedGeneric<Base>()
+  // CHECK-DIAGS-4:[[@LINE-1]]:{{[0-9]+}}: error: 'OldRenamedGeneric' has been renamed to 'RenamedGeneric'
+
+  class SwiftClass {}
+
+  // CHECK-DIAGS-3:[[@LINE+1]]:{{[0-9]+}}: error: 'OldRenamedGeneric' requires that 'SwiftClass' inherit from 'Base'
+  let _: OldRenamedGeneric<SwiftClass> = RenamedGeneric<SwiftClass>()
+  // CHECK-DIAGS-4:[[@LINE-1]]:{{[0-9]+}}: error: 'OldRenamedGeneric' requires that 'SwiftClass' inherit from 'Base'
+
+  // CHECK-DIAGS-3:[[@LINE+1]]:{{[0-9]+}}: error: 'RenamedGeneric' requires that 'SwiftClass' inherit from 'Base'
+  let _: RenamedGeneric<SwiftClass> = OldRenamedGeneric<SwiftClass>()
+  // CHECK-DIAGS-4:[[@LINE-1]]:{{[0-9]+}}: error: 'RenamedGeneric' requires that 'SwiftClass' inherit from 'Base'
+}
+
 let unrelatedDiagnostic: Int = nil