A recent commit (r286087) to the LLVM Go bindings that
changed things over to use the new attribute API broke
llgo. This commit updates llgo accordingly.
llvm-svn: 288769
At the same time, perform a number of simplifications:
- Rename go.tools directory to gotools.
- Import only the go directory; all required Go analysis code and
its dependencies have now been moved to this directory.
llvm-svn: 225825