[llvm-mca] Move llvm-mca library to llvm/lib/MCA.

Summary: See PR38731.

Reviewers: andreadb

Subscribers: mgorny, javed.absar, tschuett, gbedwell, andreadb, RKSimon, llvm-commits

Differential Revision: https://reviews.llvm.org/D55557

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@349332 91177308-0d34-0410-b5e6-96231b3b80d8
48 files changed