[ThinLTO] Ensure sanitizer passes are run

Summary:
In ThinLTO compilation, we exit populateModulePassManager early and
were not adding PM extension passes meant to run at the end of the
pipeline. This includes sanitizer passes. Add these passes before
the early exit.

A test will be added to projects/compiler-rt.

Reviewers: pcc

Subscribers: mehdi_amini, inglorion, llvm-commits

Differential Revision: https://reviews.llvm.org/D39565

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@317714 91177308-0d34-0410-b5e6-96231b3b80d8

lib/Transforms/IPO/PassManagerBuilder.cpp

@@ -548,6 +548,9 @@ void PassManagerBuilder::populateModulePassManager(
   // unrolling/vectorization/... now. We'll first run the inliner + CGSCC passes
   // during ThinLTO and perform the rest of the optimizations afterward.
   if (PrepareForThinLTO) {
+    // Ensure we perform any last passes, but do so before renaming anonymous
+    // globals in case the passes add any.
+    addExtensionsToPM(EP_OptimizerLast, MPM);
     // Rename anon globals to be able to export them in the summary.
     MPM.add(createNameAnonGlobalPass());
     return;