Use std::error_code instead of llvm::error_code.

This is an update for a llvm api change.

llvm-svn: 210688
diff --git a/clang/lib/Frontend/CompilerInstance.cpp b/clang/lib/Frontend/CompilerInstance.cpp
index f5e2749..bbcb71f 100644
--- a/clang/lib/Frontend/CompilerInstance.cpp
+++ b/clang/lib/Frontend/CompilerInstance.cpp
@@ -572,7 +572,7 @@
         llvm::sys::fs::createUniqueFile(TempPath.str(), fd, TempPath);
 
     if (CreateMissingDirectories &&
-        EC == llvm::errc::no_such_file_or_directory) {
+        EC == std::errc::no_such_file_or_directory) {
       StringRef Parent = llvm::sys::path::parent_path(OutputPath);
       EC = llvm::sys::fs::create_directories(Parent);
       if (!EC) {