llvm-svn: 169794

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

llvm-svn: 153588

llvm-svn: 152389

llvm-svn: 152355

Add first linker pass (StubsPass) which looks for calls to shared library
symbols and replaces them with calls to a StubAtom.  On ELF system, a "stub"
is a PLT entry.  Added a simple test case.

Pass a Platform object to YAML reader and writer for converting fixup kinds 
between names and values.

Change output of Resolver to be a File object instead of a vector of Atoms.
Thus, passes operate on a File instead of just Atoms.

Rework how to walk through a File's Atoms. Now iterator based instead of 
a method that visits each atom.  

llvm-svn: 152269

llvm-svn: 146844