Add an assert here in case parsing gave us a NULL compile unit.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@162498 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/DebugInfo/DWARFCompileUnit.cpp b/lib/DebugInfo/DWARFCompileUnit.cpp
index 4c98cb8..98dccac 100644
--- a/lib/DebugInfo/DWARFCompileUnit.cpp
+++ b/lib/DebugInfo/DWARFCompileUnit.cpp
@@ -94,7 +94,9 @@
      << " (next CU at " << format("0x%08x", getNextCompileUnitOffset())
      << ")\n";
 
-  getCompileUnitDIE(false)->dump(OS, this, -1U);
+  const DWARFDebugInfoEntryMinimal *CU = getCompileUnitDIE(false);
+  assert(CU && "Null Compile Unit?");
+  CU->dump(OS, this, -1U);
 }
 
 const char *DWARFCompileUnit::getCompilationDir() {