Use forward declarations for ASTDeclContextNameLookupTable and add a missing delete.

It would be nice to use OwningPtr here, but DeclContextInfo is stored in a DenseMap.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@154763 91177308-0d34-0410-b5e6-96231b3b80d8
6 files changed