Refined debug_backtrace return type

[vudaltsov]

Some explanations:

• class and type are absent in a simple function call,
• object is present only with DEBUG_BACKTRACE_PROVIDE_OBJECT option,
• args is absent when DEBUG_BACKTRACE_IGNORE_ARGS option is used.

Also removed bool from options type, since it's not there according to docs.

[orklah]

There was a time where php.net said this function could take a boolean where it's now flags:
https://web.archive.org/web/20090215184624/http://us3.php.net/debug_backtrace

Seems like it's stopped somewhere between 2009 and 2011 but some devs could be used to that. Conditional on it having the same behaviour as today, I'd vote to keep it possible

[vudaltsov]

@orklah , agree, thank you for the information!

[weirdan]

Before 5.4 the first argument used to be called $provide_object, that's where bool comes from. It can't be kept there though, as PHP would throw at runtime with strict_types enabled (https://3v4l.org/2WXuL, https://3v4l.org/vORSW), thus Psalm needs to flag it.

@vudaltsov please revert the revert.

[vudaltsov]

@weirdan , thank you! Done.

[weirdan]

@vudaltsov you will need to additionally edit either CallMap_historical (if the function had this signature before PHP 7.1) or one of the deltas (if there were changes during 7.1-8.0 period). That's why unit tests currently fail here.

[weirdan]

Thanks!