Handle AccessSpecDecl in DeclContextPrinter

This commit fixes a crash that occurs when -print-decl-contexts AST consumer
tries to print an unhandled declaration.

rdar://19467234

Differential Revision: https://reviews.llvm.org/D26964

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@290885 91177308-0d34-0410-b5e6-96231b3b80d8
(cherry picked from commit 44df50df1f5458b0d1b59d5e0654986d0d5720d8)
2 files changed