fix several problems with the protocol qualified id handling where id was implicit.

First, fix canonical type handling of these, since protocol qualified id's are always
canonical.  Next, enhance SemaType to actually make these when used (instead of int)
allowing them to actually be used when appropriate.  Finally remove a bunch of logic
relating to the mishandling of canonical types with protocol-qual id's.  This fixes
rdar://5986251

llvm-svn: 54083