Normalize comment classes

[WinterSilence]

• getReformattedText(): fix @return types, remove comment trimming to keep empty lines in comment at begin and end, optimize detection of multi-line comments
• getShortestWhitespacePrefixLen(): replace float INF to PHP_INT_MAX
• jsonSerialize(): update @psalm-return and remove redundant @return, fix nodeType

[nikic]

Test failures are legitimate.

[WinterSilence]

@nikic yes, because

remove comment trimming to keep empty lines in comment at begin and end

If you agree with these changes, I'll update the tests

[nikic]

The change to trimming is fine -- to verify, I've landed it separately as 1f504d2. This was a leftover from an older implementation, when comments were expected to have a trailing newline.

It's some of the other changes that cause problematic changes in formatting.

[WinterSilence]

@nikic hm... I'm don't see how other changes can fail tests - content changed only here

[WinterSilence]

@nikic tests failed because startLine/endLine not correct in current test: $this->startLine === $this->endLine always return true because by default they set as -1 i.e. -1=-1

[WinterSilence]

@nikic I'm fixed fake/incorrect data passing to CommentTest tests, but I'm think other failed tests must be fixes in other PR's.

[WinterSilence]

@nikic added alternative check to test instances:

|| ($this->endLine === -1 && strpos($this->text, "\n") !== false)