[LAA] Add assert check CanDoRTIFNeeded can be computed w/o RT.Need (NFC)

Add assert to ensure that CanDoRTIfNeeded can be computed w/o
RtCheck.Need, to prepare for adjusting the condition.

Author: fhahn

llvm/lib/Analysis/LoopAccessAnalysis.cpp

@@ -1325,6 +1325,8 @@ bool AccessAnalysis::canCheckPtrAtRT(
   RtCheck.Need = CanDoRT ? RtCheck.getNumberOfChecks() != 0 : MayNeedRTCheck;
 
   bool CanDoRTIfNeeded = !RtCheck.Need || CanDoRT;
+  assert(CanDoRTIfNeeded == (CanDoRT || !MayNeedRTCheck) &&
+         "CanDoRTIfNeeded depends on RtCheck.Need");
   if (!CanDoRTIfNeeded)
     RtCheck.reset();
   return CanDoRTIfNeeded;