Reintroduce parametrization over exec_call in shallow soundness proof #51
Description
The commit a34c20e#diff-e04b6681e4dfa3063d445251c60e8987dd754560f7a833c7ddc062b0f7539253R113 added fuel to the hoare triples but in doing so also removed the parametrization over exec_call in the soundness proof of exec_aux. I currently do not see a way to make this cleaner, and ideally we do not add the fuel to the definition of ExecCall. We should revisit this if/when we cut out the hoare triples from the stack.