write a line marker right before adding included file

Enclosing the original #include directive inside #if 0 adds lines,
so warning/errors messages would have the line number off in
"In file included from <file>:<line>:", so add line marker to fix this.

llvm-svn: 207756
diff --git a/clang/lib/Rewrite/Frontend/InclusionRewriter.cpp b/clang/lib/Rewrite/Frontend/InclusionRewriter.cpp
index 058960d..70b2992 100644
--- a/clang/lib/Rewrite/Frontend/InclusionRewriter.cpp
+++ b/clang/lib/Rewrite/Frontend/InclusionRewriter.cpp
@@ -383,6 +383,7 @@
           case tok::pp_import: {
             CommentOutDirective(RawLex, HashToken, FromFile, EOL, NextToWrite,
               Line);
+            WriteLineInfo(FileName, Line - 1, FileType, EOL, "");
             StringRef LineInfoExtra;
             if (const FileChange *Change = FindFileChangeLocation(
                 HashToken.getLocation())) {