The scope representation can now be either a DeclContext pointer or a

Type pointer. This allows our nested-name-specifiers to retain more
information about the actual spelling (e.g., which typedef did the
user name, or what exact template arguments were used in the
template-id?). It will also allow us to have dependent
nested-name-specifiers that don't map to any DeclContext.

llvm-svn: 67140