Revert r156141 (making RecursiveASTVisitor data recursive).  It is causing clang to blow up in memory usage on -O2 when compiling itself,
which is leading to swapping in some cases when it didn't before.  We need to see if we can make this change
without leading to a massive compile-time bloat.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@156229 91177308-0d34-0410-b5e6-96231b3b80d8
1 file changed