Add an assertion.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@3734 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/CodeGen/MachineCodeForInstruction.cpp b/lib/CodeGen/MachineCodeForInstruction.cpp
index f21e016..6156399 100644
--- a/lib/CodeGen/MachineCodeForInstruction.cpp
+++ b/lib/CodeGen/MachineCodeForInstruction.cpp
@@ -38,6 +38,7 @@
 
 MachineCodeForInstruction&
 MachineCodeForInstruction::get(const Instruction *I){
+  assert(I != NULL);
   return *(MachineCodeForInstruction*)I->getOrCreateAnnotation(MCFI_AID);
 }