[PM] Move TargetLibraryInfo into the Analysis library.

While the term "Target" is in the name, it doesn't really have to do
with the LLVM Target library -- this isn't an abstraction which LLVM
targets generally need to implement or extend. It has much more to do
with modeling the various runtime libraries on different OSes and with
different runtime environments. The "target" in this sense is the more
general sense of a target of cross compilation.

This is in preparation for porting this analysis to the new pass
manager.

No functionality changed, and updates inbound for Clang and Polly.

llvm-svn: 226078