Fix differences in codegen between Linux and Windows toolchains

Fix differences in codegen between Linux and Windows toolchains

Summary:
    There are differences in codegen between Linux and Windows due to:
    1. Using std::sort which uses quicksort which is a non-stable sort.

    2. Iterating over Set data structure where the iteration order is
       non deterministic.

Reviewers: arsenm, grosbach, junbuml, zinob, MatzeB

Subscribers: MatzeB, wdng

Differential Revision: https://reviews.llvm.org/D25695

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@284441 91177308-0d34-0410-b5e6-96231b3b80d8