Implement all-at-once block

src/blocks/scratch3_control.js

@@ -35,7 +35,8 @@ class Scratch3ControlBlocks {
             control_delete_this_clone: this.deleteClone,
             control_get_counter: this.getCounter,
             control_incr_counter: this.incrCounter,
-            control_clear_counter: this.clearCounter
+            control_clear_counter: this.clearCounter,
+            control_all_at_once: this.allAtOnce
         };
     }
 
@@ -182,6 +183,10 @@ class Scratch3ControlBlocks {
     incrCounter () {
         this._counter++;
     }
+
+    allAtOnce (args, util) {
+        util.startBranch(1, false);
+    }
 }
 
 module.exports = Scratch3ControlBlocks;

src/serialization/sb2_specmap.js

@@ -874,6 +874,15 @@ const specMap = {
         argMap: [
         ]
     },
+    'warpSpeed': {
+        opcode: 'control_all_at_once',
+        argMap: [
+            {
+                type: 'input',
+                inputName: 'SUBSTACK'
+            }
+        ]
+    },
     'touching:': {
         opcode: 'sensing_touchingobject',
         argMap: [