swift234

[cmake] Remove direct computation of dependencies on LLVM libraries and exact paths to those libraries.

Now that we have the full dependency information from LLVM/Clang, this is no
longer necessary. We will just do the *right* thing.

Additionally, since we were passing these libraries as absolute paths, cmake was
always passing through all of the given libraries even if CMake had already
added them to the link line in its non-absolute form. It is not clear to me how
if all linkers would be smart about this.

Regardless, now we just translate components to libraries and continue on our
merry way. In the future, we can even remove the llvm-build code period by just
specifying LLVM dependencies directly via LINK_LIBRARIES instead of having to do
anything with COMPONENT_DEPENDS.

But that is for a future commit.