Omnibus friend decl refactoring. Instead of cloning AST classes for friend
declarations of same, introduce a single AST class and add appropriate bits
(encoded in the namespace) for whether a decl is "real" or not. Much hackery
about previously-declared / not-previously-declared, but it's essentially
mandated by the standard that friends alter lookup, and this is at least
fairly non-intrusive.
Refactor the Sema methods specific to friends for cleaner flow and less nesting.
Incidentally solve a few bugs, but I remain confident that we can put them back.
llvm-svn: 80353
12 files changed