Make DeclContexts maintenance a bit easier.

-In DeclNodes.def, only mark as DeclContexts the top classes that directly derive from DeclContext. If the Decl has subclasses,
 it should be marked with DECL_CONTEXT_BASE.

-Use DeclNodes.def to automate the DeclContext::classof and DeclContext::CastTo definitions.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@64629 91177308-0d34-0410-b5e6-96231b3b80d8
3 files changed