Making the hardcoded string length limit of Throwable->getTraceAsString() configurable

Hi internals, By default, strings in parameter lists are truncated to 15 bytes by default in Throwable->getTraceAsString() (and Throwable->__toString() as a consequence). (in Zend/zend_exception.c in `static void _build_trace_args(zval *arg, smart_str *str)`) This limit is too short to see relevant information such as file paths, full urls, etc, which makes reporting bugs in applications inconvenient. Would there be any interest in an ini setting such as `exception_string_length_limit` as a non-negative value to raise this (either allowed to be 0 or more or 15 or more, defaulting to 15) It's possible to manually work around it by calling Throwable->getTrace(), but inconvenient, and there's always a concern about the user-space trace generation having its own issues (e.g. https://github.com/phan/phan/blob/3.0.3/src/Phan/Debug/Frame.php#L25-L132) In applications that don't have a custom exception handler, users could raise this to make creating bug reports easier. ``` php > test('12345678901234567890'); Warning: Uncaught Exception in php shell code:1 Stack trace: #0 php shell code(1): test('123456789012345...') #1 {main}   thrown in php shell code on line 1 ``` Thanks, - Tyson