Fix failing assertion inside MSVC STL in debug builds

Fix failing assertion inside MSVC STL in debug builds

When using FunctionObject's call() method, we use std::copy to copy the
arguments over to the new call context. Unfortunately std::copy has an
assertion in there to check that we're not copying out of bounds.  What the STL
doesn't know is that the Value args[1] array is dynamically allocated and
easily expands beyond just one entry.

Fall back to copying by hand to work around this issue.

Task-number: QTBUG-38195
Change-Id: I6e254b1c893ccf5cad2358179cda1b07b00228e0
Reviewed-by: Friedemann Kleint <Friedemann.Kleint@digia.com>
Reviewed-by: Lars Knoll <lars.knoll@digia.com>