[gn build] Port 2ab4c28

Author: llvmgnsyncbot

llvm/utils/gn/secondary/clang/lib/Interpreter/BUILD.gn

@@ -26,6 +26,7 @@ static_library("Interpreter") {
   sources = [
     "CodeCompletion.cpp",
     "DeviceOffload.cpp",
+    "IncrementalAction.cpp",
     "IncrementalExecutor.cpp",
     "IncrementalParser.cpp",
     "Interpreter.cpp",