Added documentation for MergeFunctions pass:
Pass looks for equivalent functions that are mergable and folds them.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@223931 91177308-0d34-0410-b5e6-96231b3b80d8
[Hexagon] Adding JR class predicated call reg instructions.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@223933 91177308-0d34-0410-b5e6-96231b3b80d8