make asan work at -O0, llvm part. Patch by glider@google.com

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@145530 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Transforms/IPO/PassManagerBuilder.cpp b/lib/Transforms/IPO/PassManagerBuilder.cpp
index 8fdfd72..7837ad9 100644
--- a/lib/Transforms/IPO/PassManagerBuilder.cpp
+++ b/lib/Transforms/IPO/PassManagerBuilder.cpp
@@ -101,6 +101,7 @@
       MPM.add(Inliner);
       Inliner = 0;
     }
+    addExtensionsToPM(EP_EnabledOnOptLevel0, MPM);
     return;
   }
 
@@ -340,4 +341,3 @@
   PassManagerBase *LPM = unwrap(PM);
   Builder->populateLTOPassManager(*LPM, Internalize, RunInliner);
 }
-