CodeExtractor : Add ability to preserve profile data.

Added ability to estimate the entry count of the extracted function and
the branch probabilities of the exit branches.

Patch by River Riddle!

Differential Revision: https://reviews.llvm.org/D22744

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@277411 91177308-0d34-0410-b5e6-96231b3b80d8
11 files changed