Propagate error in LazyEmittingLayer::removeModule.

Summary:
Besides being the better thing to do, not doing so will triggers an assert with LLVM_ENABLE_ABI_BREAKING_CHECKS.

Reviewers: lhames

Reviewed By: lhames

Subscribers: llvm-commits

Differential Revision: https://reviews.llvm.org/D36700

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@310906 91177308-0d34-0410-b5e6-96231b3b80d8
1 file changed