message: Add the `cosmwasm_1_2` export
diff: @@ -45,6 +45,10 @@ extern "C" fn requires_stargate() -> () {}
  #[no_mangle]
  extern "C" fn requires_cosmwasm_1_1() -> () {}
  +#[cfg(feature = "cosmwasm_1_2")]
  +#[no_mangle]
  +extern "C" fn requires_cosmwasm_1_2() -> () {}
  +
  /// interface_version_* exports mark which Wasm VM interface level this contract is compiled for.
  /// They can be checked by cosmwasm_vm.
  /// Update this whenever the Wasm VM interface breaks.
  