Description:
------------
With the addition of the splat operator in PHP 5.6 it became very useful to have an array of objects and pass them to a method and still have type checking (even when using splat, such as: foo(\DateTime ...$dates).

I'm not sure if this is practical/possible to implement, but it would be very useful to use that same sort of type checking with the splat operator for instanceof checks, such as: if (...$dates instanceof \DateTime). Currently that syntax produces "PHP Parse error:  syntax error, unexpected '...' (T_ELLIPSIS)".

Test script:
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$foo = [ new \DateTime(), new \DateTime()];

if (...$foo instanceof \DateTime) {
    echo "DateTime";
}

Expected result:
----------------
DateTime

Actual result:
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PHP Parse error:  syntax error, unexpected '...' (T_ELLIPSIS)