now Reader and Writer subclasses for each file format. Each Reader and
Writer subclass defines an "options" class which controls how that Reader
or Writer operates.
llvm-svn: 157774
class. Change Resolver to no longer use Platform. Core linking
now issues errors directly. We need to factor that out later.
Rework how Darwin executable writer finds "main" atom. It now
adds to core linking an Atom which has a Reference to "main".
llvm-svn: 155060
Nick Kledzik