o) Add a 'Location' class that represents the four properties of a
physical location
o) Enhance 'SourceLocation' to provide 'expansion' and 'spelling'
locations, maintaining backwards compatibility with existing code by
forwarding the four properties to 'expansion'.
o) Update the implementation to use 'clang_getExpansionLocation'
instead of the deprecated 'clang_getInstantiationLocation', which
has been present since 2011.
o) Update the implementation of 'clang_getSpellingLocation' to actually
obtain spelling location instead of file location.
llvm-svn: 316278
5b3fa2cd99