ASTUnit: Don't create an LLVMContext, it shouldn't be needed.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@90310 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Frontend/ASTUnit.cpp b/lib/Frontend/ASTUnit.cpp
index 6e3a1e1..ac21338 100644
--- a/lib/Frontend/ASTUnit.cpp
+++ b/lib/Frontend/ASTUnit.cpp
@@ -30,7 +30,6 @@
 #include "clang/Basic/TargetOptions.h"
 #include "clang/Basic/TargetInfo.h"
 #include "clang/Basic/Diagnostic.h"
-#include "llvm/LLVMContext.h"
 #include "llvm/System/Host.h"
 #include "llvm/System/Path.h"
 using namespace clang;
@@ -200,7 +199,7 @@
                                              bool OnlyLocalDecls,
                                              bool UseBumpAllocator) {
   // Create the compiler instance to use for building the AST.
-  CompilerInstance Clang(&llvm::getGlobalContext(), false);
+  CompilerInstance Clang;
   llvm::OwningPtr<ASTUnit> AST;
   NullAction Act;