Support formatting of preprocessor branches.

We now correctly format:
  void SomeFunction(int param1,
  #ifdef X
                    NoTemplate param2,
  #else
                    template <
  #ifdef A
                        MyType<Some> >
  #else
                        Type1, Type2>
  #endif
                    param2,
  #endif
                    param3) {
    f();
  }

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@192503 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Format/ContinuationIndenter.h b/lib/Format/ContinuationIndenter.h
index c3642d2..60e0027 100644
--- a/lib/Format/ContinuationIndenter.h
+++ b/lib/Format/ContinuationIndenter.h
@@ -250,7 +250,7 @@
   unsigned Column;
 
   /// \brief The token that needs to be next formatted.
-  const FormatToken *NextToken;
+  FormatToken *NextToken;
 
   /// \brief \c true if this line contains a continued for-loop section.
   bool LineContainsContinuedForLoopSection;