findBlockScoped(name) {
    if (this.vars[name]) {
      return this.vars[name];
    }
    return this.parent.findBlockScoped(name);
  }
Looks up variables from block scope.

Either from the current block, or any parent block.
When variable found from function scope instead,
returns empty array to signify it's not properly block-scoped.

@param  {String} name Variable name
@return {Variable[]} The found variables (empty array if none found)