Safeguard DBG_VALUE handling. Unbreaks the ASAN buildbot.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@186014 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/CodeGen/InlineSpiller.cpp b/lib/CodeGen/InlineSpiller.cpp
index 2ab58a7..8910652 100644
--- a/lib/CodeGen/InlineSpiller.cpp
+++ b/lib/CodeGen/InlineSpiller.cpp
@@ -1152,7 +1152,8 @@
     // Debug values are not allowed to affect codegen.
     if (MI->isDebugValue()) {
       // Modify DBG_VALUE now that the value is in a spill slot.
-      uint64_t Offset = MI->getOperand(1).getImm();
+      bool IsIndirect = MI->getOperand(1).isImm();
+      uint64_t Offset = IsIndirect ? MI->getOperand(1).getImm() : 0;
       const MDNode *MDPtr = MI->getOperand(2).getMetadata();
       DebugLoc DL = MI->getDebugLoc();
       DEBUG(dbgs() << "Modifying debug info due to spill:" << "\t" << *MI);