Fix dependency tracking for abstract contracts for Yul codegen

test/libsolidity/semanticTests/freeFunctions/free_runtimecode.sol

@@ -11,5 +11,7 @@ contract D {
     return test();
   }
 }
+// ====
+// compileViaYul: true
 // ----
 // f() -> true

test/libsolidity/semanticTests/freeFunctions/new_operator.sol

@@ -11,5 +11,7 @@ contract D {
     return test();
   }
 }
+// ====
+// compileViaYul: true
 // ----
 // f() -> 2