Remove most type traits from qtypetraits.h, but keep the custom
implementation of is_signed/is_unsigned. This gets rid of
BSD-3 licensed code from Google in a public header (hugh!).
The custom implementations for is_signed/is_unsigned are kept
because the implementations in gcc's standard headers do not
work as we expect for enums - both is_signed and is_unsigned
always returns false there - see also
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=59027
[ChangeLog][QtCore][General] Qt now relies on type traits from
the C++ standard library.
Change-Id: I3f2188b46949f04ca4482a6ac9afd3482103f0e1
Reviewed-by: Thiago Macieira <thiago.macieira@intel.com>
ed7f77071d