Don't throw exceptions from operator new by default (#6312)
Don't throw exceptions from operator new by default (#6312)

Default mode (no exceptions) will no longer use the stdc++ library new
allocator when there is not enough memory.  Instead, it will return
nullptr.  This is the pre-exceptions-available behavior (2.5.0 and
earlier).

When exceptions are enabled, use the real new and throw exceptions that
can be caught at higher levels, or which will crash the app with an
uncaught exception if they're not handled.

Update to #6309
esp8266/Arduino,esp8266/Arduino,sticilface/Arduino,sticilface/Arduino,esp8266/Arduino,sticilface/Arduino,esp8266/Arduino,esp8266/Arduino,sticilface/Arduino,sticilface/Arduino