Fix yul ast ID to 0 instead of 1.

test/cmdlineTests/standard_yul/output.json

@@ -169,7 +169,7 @@
                 "nodeType": "YulObject",
                 "subObjects": []
             },
-            "id": 1
+            "id": 0
         }
     }
 }

test/cmdlineTests/standard_yul_object/output.json

@@ -179,7 +179,7 @@ data_4e03657aea45a94fc7d47ba826c8d667c0d1e6e33a64a036ec44f58fa12d6c45 616263
                     }
                 ]
             },
-            "id": 1
+            "id": 0
         }
     }
 }

test/cmdlineTests/standard_yul_object_name/output.json

@@ -258,7 +258,7 @@ sub_0: assembly {
                     }
                 ]
             },
-            "id": 1
+            "id": 0
         }
     }
 }

test/cmdlineTests/standard_yul_optimiserSteps/output.json

@@ -166,7 +166,7 @@
                 "nodeType": "YulObject",
                 "subObjects": []
             },
-            "id": 1
+            "id": 0
         }
     }
 }

test/cmdlineTests/standard_yul_optimized/output.json

@@ -161,7 +161,7 @@
                 "nodeType": "YulObject",
                 "subObjects": []
             },
-            "id": 1
+            "id": 0
         }
     }
 }