C++: use UnmodeledDefinition in UnmodeledUse

cpp/ql/src/semmle/code/cpp/ir/implementation/aliased_ssa/internal/SSAConstruction.qll

@@ -153,7 +153,7 @@ cached private module Cached {
               else
                 result = getPhiInstruction(instruction.getFunction(), defBlock, vvar)
             )
-          )
+          ) 
           else (
             result = instruction.getFunctionIR().getUnmodeledDefinitionInstruction()
           )
@@ -168,12 +168,17 @@ cached private module Cached {
           result = getNewInstruction(oldDefinition)
         )
       )
-      else
+      else 
         result = getNewInstruction(oldOperand.getDefinitionInstruction())
     ) or
     instruction.getTag() = ChiTag(getOldInstruction(result)) and
     tag instanceof ChiPartialOperandTag
     or
+    instruction instanceof UnmodeledUseInstruction and
+    tag instanceof UnmodeledUseOperandTag and
+    result  instanceof UnmodeledDefinitionInstruction and
+    instruction.getFunction() = result.getFunction()
+    or
     result = getChiInstructionTotalOperand(instruction.(ChiInstruction), tag.(ChiTotalOperandTag))
   }
 

cpp/ql/src/semmle/code/cpp/ir/implementation/raw/internal/TranslatedFunction.qll

@@ -218,6 +218,11 @@ class TranslatedFunction extends TranslatedElement,
       result.getFunction() = func and
       result.hasMemoryResult()
     ) or
+    (
+      tag = UnmodeledUseTag() and
+      operandTag instanceof UnmodeledUseOperandTag and
+      result = getUnmodeledDefinitionInstruction()
+    ) or
     (
       tag = ReturnTag() and
       not getReturnType() instanceof VoidType and

cpp/ql/src/semmle/code/cpp/ir/implementation/unaliased_ssa/internal/SSAConstruction.qll

@@ -174,6 +174,11 @@ cached private module Cached {
     instruction.getTag() = ChiTag(getOldInstruction(result)) and
     tag instanceof ChiPartialOperandTag
     or
+    instruction instanceof UnmodeledUseInstruction and
+    tag instanceof UnmodeledUseOperandTag and
+    result  instanceof UnmodeledDefinitionInstruction and
+    instruction.getFunction() = result.getFunction()
+    or
     result = getChiInstructionTotalOperand(instruction.(ChiInstruction), tag.(ChiTotalOperandTag))
   }