* Renames few tests which had extension objtxt to test
* created core directory that contains all the core tests

llvm-svn: 189720

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

and adds a new file ReaderWriterYAML.cpp that uses YAML I/O.

Lots of tweaks to test suite for slightly different YAML encoding.

llvm-svn: 171592

shared library) and AbsoluteAtoms (proxy atoms for absolute address (e.g. ROM)).
Redesign weak importing as can-be-null-at-runtime and can-be-null-at-build-time.
Add lots of test cases for all the above.

llvm-svn: 151204