[nfc][cxx-interop] Add diagnostics for invalid custom reference counting operations.

Author: zoecarver

include/swift/AST/DiagnosticsIRGen.def

@@ -59,10 +59,19 @@ ERROR(temporary_allocation_alignment_not_positive,none,
 ERROR(temporary_allocation_alignment_not_power_of_2,none,
       "alignment value must be a power of two", ())
 
-ERROR(foreign_reference_types_unsupported,none,
-      "attempt to use a foreign reference type in a generic context. "
-      "Foreign reference types are currently not supported. Using foreign "
-      "reference types in a generic context is not yet implemented.", ())
+ERROR(foreign_reference_types_cannot_find_retain,none,
+      "cannot find retain function '%0'.", (StringRef))
+
+ERROR(foreign_reference_types_cannot_find_release,none,
+      "cannot find release function '%0'.", (StringRef))
+
+ERROR(foreign_reference_types_invalid_retain,none,
+      "specified retain function '%0' is invalid. Retain must have exactly one "
+      "argument of type '%1'", (StringRef, StringRef))
+
+ERROR(foreign_reference_types_invalid_release,none,
+      "specified release function '%0' is invalid. Release must have exactly "
+      "one argument of type '%1'", (StringRef, StringRef))
 
 #define UNDEFINE_DIAGNOSTIC_MACROS
 #include "DefineDiagnosticMacros.h"

lib/ClangImporter/ImportDecl.cpp

@@ -2418,6 +2418,8 @@ namespace {
         }
       }
 
+      
+
       result->setMemberLoader(&Impl, 0);
       return result;
     }