Make 'LangOptions' in CompilerInvocation a heap-allocated, reference counted object.  I discovered that llvm::RefCountedBase<T> has
a bug where the reference count is copied in the copy constructor, which means that there were cases when the CompilerInvocation
objects created by ASTUnit were actually leaked.  When I fixed that bug locally, it showed that a whole bunch of code assumed
that the LangOptions object that was part of CompilerInvocation was still alive.  By making it heap-allocated and reference counted,
we can keep it around after the CompilerInvocation object goes away.

As part of this change, change CompilerInvocation:getLangOptions() to return a pointer, acting as another clue that this
object may outlive the CompilerInvocation object.

This commit doesn't fix the CompilerInvocation leak itself.  That will come when I commit the fix to llvm::RefCountedBase<T> to
mainline LLVM.

llvm-svn: 144930
diff --git a/clang/tools/arcmt-test/arcmt-test.cpp b/clang/tools/arcmt-test/arcmt-test.cpp
index e47e815..3f91fcf 100644
--- a/clang/tools/arcmt-test/arcmt-test.cpp
+++ b/clang/tools/arcmt-test/arcmt-test.cpp
@@ -125,7 +125,7 @@
     return true;
   }
 
-  if (!CI.getLangOpts().ObjC1)
+  if (!CI.getLangOpts()->ObjC1)
     return false;
 
   arcmt::checkForManualIssues(CI,
@@ -167,13 +167,13 @@
     return true;
   }
 
-  if (!origCI.getLangOpts().ObjC1)
+  if (!origCI.getLangOpts()->ObjC1)
     return false;
 
   MigrationProcess migration(origCI, DiagClient);
 
   std::vector<TransformFn>
-    transforms = arcmt::getAllTransformations(origCI.getLangOpts().getGC());
+    transforms = arcmt::getAllTransformations(origCI.getLangOpts()->getGC());
   assert(!transforms.empty());
 
   llvm::OwningPtr<PrintTransforms> transformPrinter;