[Sema] [AST] NFC: Remove @runtimeMetadata related code

Author: xedin

lib/Sema/CMakeLists.txt

@@ -67,7 +67,6 @@ add_swift_host_library(swiftSema STATIC
   TypeCheckProtocolInference.cpp
   TypeCheckRegex.cpp
   TypeCheckRequestFunctions.cpp
-  TypeCheckRuntimeMetadataAttr.cpp
   TypeCheckStmt.cpp
   TypeCheckStorage.cpp
   TypeCheckSwitchStmt.cpp