Fix nondeterminism introduced in r353954

DenseMap iteration order is not guaranteed, use MapVector instead.

Fix provided by srhines.

Differential Revision: https://reviews.llvm.org/D59807

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@356988 91177308-0d34-0410-b5e6-96231b3b80d8
3 files changed