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

llvm-svn: 155847

Add SharedLibraryFile and ArchiveLibraryFile subclasses of File.

Add command line options to lld-core to set various ResolverOptions settings
and added lots of test cases to verify the options work.

llvm-svn: 155183