[Inliner] Assert that the computed inline threshold is non-negative.

Reviewers: chandlerc

Subscribers: haicheng, llvm-commits

Differential Revision: https://reviews.llvm.org/D56409

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@350751 91177308-0d34-0410-b5e6-96231b3b80d8
2 files changed