Move HeaderSearchOptions into the Lex library, make it intrusively
reference-counted, and hold a reference to it in HeaderSearch.

llvm-svn: 166583
diff --git a/clang/lib/Frontend/ASTUnit.cpp b/clang/lib/Frontend/ASTUnit.cpp
index 855b27a..39b3437 100644
--- a/clang/lib/Frontend/ASTUnit.cpp
+++ b/clang/lib/Frontend/ASTUnit.cpp
@@ -709,7 +709,10 @@
   AST->SourceMgr = new SourceManager(AST->getDiagnostics(),
                                      AST->getFileManager(),
                                      UserFilesAreVolatile);
-  AST->HeaderInfo.reset(new HeaderSearch(AST->getFileManager(),
+  AST->HSOpts = new HeaderSearchOptions();
+  
+  AST->HeaderInfo.reset(new HeaderSearch(AST->HSOpts,
+                                         AST->getFileManager(),
                                          AST->getDiagnostics(),
                                          AST->ASTFileLangOpts,
                                          /*Target=*/0));