* Include the source location in Closure names
This change makes stack traces involving Closures, especially multiple
different Closures, much more useful, because it's more easily visible *which*
closure was called for a given stack frame.
The implementation is similar to that of anonymous classes which already
include the file name and line number within their generated classname.
* Update scripts/dev/bless_tests.php for closure naming
* Adjust existing tests for closure naming
* Adjust tests for closure naming that were not caught locally
* Drop the namespace from closure names
This is redundant with the included filename.
* Include filename and line number as separate keys in Closure debug info
* Fix test
* Fix test
* Include the surrounding class and function name in closure names
* Fix test
* Relax test expecations
* Fix tests after merge
* NEWS / UPGRADING
If an argument error refers to a variadic argument, we normally
do not print the name of the variadic (as it is not referring to
an individual argument, but to the collection of all of them).
However, this was not the case for the userland argument type
error message, which did it's own formatting.
Closes GH-6101.
