A provision in a written contract between an employer and an association of employees, a labor union, trade union, or craft union, or between an association of employers and an association of employees, labor unions, trade unions, or craft unions, to submit to arbitration any and all controversies relative to the execution of a new contract upon the termination of an existing contract, as provided for in writing in the existing contract, shall be valid, irrevocable, and enforceable, except upon any grounds that exist in law or in equity for the revocation of the contract; and it is not a defense to the enforceability of the provision to submit to arbitration that the issue or issues that the arbitrator or arbitrators must decide is not one that could have formed the basis of an action at law or suit in equity.