[Clock] Add get/setMicroseconds()

[nicolas-grekas]

Q	A
Branch?	7.1
Bug fix?	no
New feature?	yes
Deprecations?	no
Issues	-
License	MIT

Polyfilling php/php-src#12557

[stof]

One question here: how confident are we that the new PHP method won't be changed between now and the PHP 8.4 feature freeze in a way that would break our child method ? Symfony 7.1 will be released 6 months before PHP 8.4.
If we are not 100% confident, we should delay that to Symfony 7.2 to avoid making it impossible to make the component compatible with PHP 8.4 without BC break.

[nicolas-grekas]

The only thing that could change is the return type of the native methods, which we already set (they're tentative-return-types in the engine for now). I'm 99.9% confident this is going to be compatible with 8.4 :)

[OskarStark]

Just in case would it be possible to mark the methods experimental?

[fabpot]

Thank you @nicolas-grekas.

[marc-mabe]

FYI php/php-src#13486 Not sure it it goes through