Rework QSimpleParsedNumber to store a qsizetype whose sign serves as
ok flag (positive is ok, zero and negative are not) and magnitude is
the number of characters used. This replaces an endptr that was set to
null to indicate !ok, but that deprived us of end-of-parse
information, which is needed for number-parsing. In particular, JS's
parsing of numbers accepts overflow (where qstrntod() flags it as
invalid) as infinity; so qstrntod() does need to say how long the
overflowing (but JS-valid, none the less) number-text was.
Modify all callers of functions using this (recently-introduced) type
and add tests that fail without this fix.
Fixes: QTBUG-108628
Change-Id: I416cd213e1fb8101b1af5a6d43615b970a5db9b4
Reviewed-by: Ulf Hermann <ulf.hermann@qt.io>
6c435e5dd4