swift234

Don't link llvm statically into libswiftOptimizeARC.a. Actually link libswiftOptimizeARC.a into SwiftARCPasses.dylib.

This patch fixes a number of issues:

1. We were not linking libswiftOptimizeARC.a into SwiftARCPasses.dylib.
2. If you did perform that linking since libswiftOptimizeARC.a had a bunch of
llvm statically linked into it, opt would see multiple instances of certain
options causing it to error out.

Now we don't statically link in a ton of LLVM into libswiftOptimizeARC.a and
properly link libswiftOptimizeARC.a into SwiftARCPasses.dylib.

Swift SVN r14557