AST: Map ParamDecl types out of context when mangling

Author: slavapestov

lib/AST/Mangle.cpp

@@ -489,7 +489,13 @@ Type Mangler::getDeclTypeForMangling(const ValueDecl *decl,
   if (!decl->hasInterfaceType())
     return ErrorType::get(C);
 
+  // FIXME: Interface types for ParamDecls
   Type type = decl->getInterfaceType();
+  if (type->hasArchetype()) {
+    assert(isa<ParamDecl>(decl));
+    type = ArchetypeBuilder::mapTypeOutOfContext(
+        decl->getDeclContext(), type);
+  }
 
   initialParamDepth = 0;
   CanGenericSignature sig;