[preprocessor] When #including something that contributes no tokens at all,
don't recursively continue lexing.

This avoids a stack overflow with a sequence of many empty #includes.
rdar://11988695

llvm-svn: 167801
diff --git a/clang/lib/Lex/PreprocessorLexer.cpp b/clang/lib/Lex/PreprocessorLexer.cpp
index a64c84d..390d4c4 100644
--- a/clang/lib/Lex/PreprocessorLexer.cpp
+++ b/clang/lib/Lex/PreprocessorLexer.cpp
@@ -22,7 +22,7 @@
 PreprocessorLexer::PreprocessorLexer(Preprocessor *pp, FileID fid)
   : PP(pp), FID(fid), InitialNumSLocEntries(0),
     ParsingPreprocessorDirective(false),
-    ParsingFilename(false), LexingRawMode(false) {
+    ParsingFilename(false), LexingRawMode(false), EnableIncludedEOF(false) {
   if (pp)
     InitialNumSLocEntries = pp->getSourceManager().local_sloc_entry_size();
 }