Use static_assert for STATIC_ASSERT for C++11 onwards
C++11 has a
static_assert (COND, MESSAGE)
which gives more readable error messages for STATIC_ASSERT than our
current implementation.
This patch makes us use it if __cplusplus >= 201103L
There's also a provisional static_assert (COND) in C++1z, but presumably
we should wait until that one is fully standardized before using it.
gcc/ChangeLog:
* system.h (STATIC_ASSERT): Use static_assert if building
with C++11 onwards.
git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@238786 138bc75d-0d04-0410-961f-82ee72b054a4