Fix PR5633 by making the preprocessor handle the case where we can
stat a file but where mmaping it fails.  In this case, we emit an
error like:
t.c:1:10: fatal error: error opening file '../../foo.h'

instead of "cannot find file".



git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@90110 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Rewrite/HTMLRewrite.cpp b/lib/Rewrite/HTMLRewrite.cpp
index b4bf419..342b0e6 100644
--- a/lib/Rewrite/HTMLRewrite.cpp
+++ b/lib/Rewrite/HTMLRewrite.cpp
@@ -353,7 +353,8 @@
   RewriteBuffer &RB = R.getEditBuffer(FID);
 
   const SourceManager &SM = PP.getSourceManager();
-  Lexer L(FID, SM, PP.getLangOptions());
+  const llvm::MemoryBuffer *FromFile = SM.getBuffer(FID);
+  Lexer L(FID, FromFile, SM, PP.getLangOptions());
   const char *BufferStart = L.getBufferStart();
 
   // Inform the preprocessor that we want to retain comments as tokens, so we
@@ -444,7 +445,8 @@
   const SourceManager &SM = PP.getSourceManager();
   std::vector<Token> TokenStream;
 
-  Lexer L(FID, SM, PP.getLangOptions());
+  const llvm::MemoryBuffer *FromFile = SM.getBuffer(FID);
+  Lexer L(FID, FromFile, SM, PP.getLangOptions());
 
   // Lex all the tokens in raw mode, to avoid entering #includes or expanding
   // macros.