Improvements 🔧

Support for literal-string PHPDoc type inspired by is_literal() RFC (https://wiki.php.net/rfc/is_literal), #5507
Support bool as template type bound (phpstan/phpstan-src@9d191f9)
Support float as template type bound (phpstan/phpstan-src@4e7d6c1), #5331
Make ReflectionAttribute generic (#640, #643), thanks @vhenzl!
Implemented math on IntegerRangeType and ConstantIntegerType (#637), #4843, thanks @staabm!
Support non-empty-array type in [] != $arr conditions (#649), thanks @staabm!
Optimization - do not sort huge unions (phpstan/phpstan-src@5a44c29), #5500
Optimize calculating scalar values from huge unions (phpstan/phpstan-src@a6ca5f7), #5527
Update PHP 8 stubs (phpstan/phpstan-src@a82605f)

Bugfixes 🐛

Reflection: fixed context of invoking a trait method (phpstan/phpstan-src@89ceb6a), #5497
Union normalization - do not take template types apart (phpstan/phpstan-src@3b17c0e)
self::CONSTANT can be precise even with PHPDoc type (phpstan/phpstan-src@5010ef4), #5517
Fix CallableType's string type assumptions (phpstan/phpstan-src@9a9f193)
OptimizedDirectorySourceLocator - fixed crash when parsing Text.php of nl_BE from Faker (phpstan/phpstan-src@a09a98d), #5525
Fix ?parent in return type (phpstan/phpstan-src@30c9b01), #5529
Fixed missing return rule for native mixed type (phpstan/phpstan-src@03d8312)
Make mixin method static if there's __callStatic() in the class (phpstan/phpstan-src@114a38f), #5536
added sizeof() as alias of count() for Smaller/SmallerOrEqual (#647, #648), #4843, thanks @staabm!
Refactor PreInc and PreDec (phpstan/phpstan-src@a6a23dc), #1870
Fix inferring TemplateUnionType ((phpstan/phpstan-src@1b5710a), #5562

substr_count returns non-negative integer (phpstan/phpstan-src@8db058a), #5513
mb_str_split() / str_split() always returns non-empty-array (#633), thanks @staabm!
Third parameter of sodium_base642bin() is optional. (#644), thanks @tehbeard!
Make filter_var() return non-empty-string if input is non-empty (#642), thanks @devbanana!
use positive-int in iterator_count() / iterator_apply() (#646), thanks @staabm!
use positive-int in array_count_values() (#645), thanks @staabm!
filter_var() should return non empty string only when it will not be sanitized (#650), thanks @devbanana!
Sync parse_url signature with PHP 8 (phpstan/phpstan-src@f7c6464)