llvm-svn: 178918

llvm-svn: 178914

The major changes are:
1) LinkerOptions has been merged into TargetInfo
2) LinkerInvocation has been merged into Driver
3) Drivers no longer convert arguments into an intermediate (core) argument 
   list, but instead create a TargetInfo object and call setter methods on 
   it. This is only how in-process linking would work. That is, you can 
   programmatically set up a TargetInfo object which controls the linking.
4) Lots of tweaks to test suite to work with driver changes
5) Add the DarwinDriver
6) I heavily doxygen commented TargetInfo.h

Things to do after this patch is committed:
a) Consider renaming TargetInfo, given its new roll. 
b) Consider pulling the list of input files out of TargetInfo. This will 
   enable in-process clients to create one TargetInfo the re-use it with 
   different input file lists.
c) Work out a way for Drivers to format the warnings and error done in 
   core linking.

llvm-svn: 178776

llvm-svn: 177079

I really would have liked to split this patch up, but it would greatly
complicate the lld-core and lld drivers having to deal with both
{Reader,Writer}Option and TargetInfo.

llvm-svn: 173217

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