Make sure that we have File IDs for all of the unsaved files before we
deserialize diagnostics.

llvm-svn: 99426
diff --git a/clang/tools/CIndex/CIndexDiagnostic.cpp b/clang/tools/CIndex/CIndexDiagnostic.cpp
index 6aed49e..f4454d4 100644
--- a/clang/tools/CIndex/CIndexDiagnostic.cpp
+++ b/clang/tools/CIndex/CIndexDiagnostic.cpp
@@ -265,6 +265,7 @@
     }
     
     SourceMgr.overrideFileContents(File, Buffer);
+    SourceMgr.createFileID(File, SourceLocation(), SrcMgr::C_User);
   }
 
   // Parse the diagnostics, emitting them one by one until we've