Treat the float 2**63 as above every int in IntegerRangeType factories

[zonuexe]

IntegerRangeType::createAllSmallerThan() and createAllGreaterThanOrEqualTo() mishandle a float argument of exactly 2**63 (9.2233720368547758E18, i.e. PHP_INT_MAX + 1).

The guard $value > PHP_INT_MAX compares against PHP_INT_MAX converted to float, which is 2**63 itself, so the guard is false for exactly 2**63. The code then reaches (int) ceil($value), which emits "The float 9.223372036854776E+18 is not representable as an int, cast occurred" and gives the wrong type:

call	before	after
createAllSmallerThan(2**63)	*NEVER* + warning	int
createAllGreaterThanOrEqualTo(2**63)	int<min, max> + warning	*NEVER*

As a result, if ($i < 9.2233720368547758E18) on an int narrowed $i to never in the truthy branch. On the PHP_INT_MIN side, a float -2**63 is exactly PHP_INT_MIN and can be cast safely, and all four factories already return the right types there.

The first commit changed these two guards to >=, like the other two factories and like #6541 on 2.3.x. That is right on 64-bit builds, but on 32-bit builds PHP_INT_MAX (2147483647) is exact as a float, so >= would make createAllGreaterThanOrEqualTo(2147483647.0) return *NEVER* although the int PHP_INT_MAX satisfies it. The second commit instead decides on the ceil() that is about to be cast, and compares it with PHP_INT_MAX + 1.0, the first float above PHP_INT_MAX on both widths. On 64-bit the result is the same as with >=. The code is the same as #6546 proposes for 2.3.x, so the two branches agree when 2.2.x is merged up.

This surfaced as warnings during self-analysis of code comparing an int|float with 9.2233720368547758E18, which #6539 worked around by comparing only a float.

Tests:

• IntegerRangeTypeTest::testCreateFromFloat covers all four factories at 2**63, the largest float below it, -2**63, and the largest float below -2**63. These literals are 64-bit int bounds, so it is skipped on 32-bit hosts.
• IntegerRangeTypeTest::testFloatBounds is the same as in Compare float bounds against PHP_INT_MAX + 1.0 in IntegerRangeType #6546: the bounds around PHP_INT_MAX and PHP_INT_MIN, with expectations that depend on PHP_INT_SIZE. On linux/386 (Docker php:8.5-cli, PHP 8.5.10), two of its rows fail with the first commit alone, and all pass with the second.
• An nsrt test covers <, <=, > and >= between an int and 9.2233720368547758E18. It passes on linux/386 too.