PHP 7.4 issues

1) vendor/Gcp/guzzlehttp/promises/src/functions.php: Function each() is deprecated since PHP 7.2; Use a foreach loop instead
2) vendor/Gcp/guzzlehttp/guzzle/src/functions.php: The default value of the idn_to_ascii() $variant parameter has changed from INTL_IDNA_VARIANT_2003 to INTL_IDNA_VARIANT_UTS46 in PHP 7.4. For optimal cross-version compatibility, the $variant parameter should be explicitly set
3) vendor/Gcp/google/cloud-storage/src/SigningHelper.php: Since PHP 7.0, functions inspecting arguments, like func_get_args(), no longer report the original value as passed to a parameter, but will instead provide the current value. The parameter “$options” was used, and possibly changed (by reference), on line 73.
4) vendor/Gcp/google/cloud-core/src/Batch/InMemoryConfigStorage.php: Visibility for magic method __sleep must be public. Found: private
5) classes/as3cf-plugin-compatibility.php: Since PHP 7.0, functions inspecting arguments, like debug_backtrace(), no longer report the original value as passed to a parameter, but will instead provide the current value. The parameter “$url” was used, and possibly changed (by reference), on line 429.