FileCollector.h - reduce Twine.h include to forward declaration. NFC.

llvm/include/llvm/Support/FileCollector.h

@@ -12,13 +12,13 @@
 #include "llvm/ADT/SmallVector.h"
 #include "llvm/ADT/StringMap.h"
 #include "llvm/ADT/StringSet.h"
-#include "llvm/ADT/Twine.h"
 #include "llvm/Support/VirtualFileSystem.h"
-
 #include <mutex>
+#include <string>
 
 namespace llvm {
 class FileCollectorFileSystem;
+class Twine;
 
 /// Captures file system interaction and generates data to be later replayed
 /// with the RedirectingFileSystem.

llvm/lib/Support/FileCollector.cpp

@@ -8,6 +8,7 @@
 
 #include "llvm/Support/FileCollector.h"
 #include "llvm/ADT/SmallString.h"
+#include "llvm/ADT/Twine.h"
 #include "llvm/Support/FileSystem.h"
 #include "llvm/Support/Path.h"
 #include "llvm/Support/Process.h"