[LoopUnroll] Enable PGO-based loop peeling by default.

This enables peeling of loops with low dynamic iteration count by default,
when profile information is available.

Differential Revision: https://reviews.llvm.org/D27734


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@295796 91177308-0d34-0410-b5e6-96231b3b80d8
2 files changed