The comparator function used at ksort in SORT_REGULAR mode
need to be consistent with basic comparison rules. These rules
were changed in PHP-8.0 for numeric strings, but comparator
used at ksort kept the old behaviour. It leads to inconsistent
situations, when after ksort the first key is GREATER than some
of the next ones by according to the basic comparison operators.
Closes GH-9293.
var_dump() is debugging functionality, so it should print
floating-point numbers accurately. We do this by switching
to serialize_precision, which (by default) will print with
as much precision as necessary to preserve the exact value
of the float.
This also affects debug_zval_dump().
Closes GH-5172.