Adding a generic backtrace to better_compile and better_exec is pointless,
therefore reraise the exception as a bb.BBHandledException so the
generic code doesn't confuse the user even more.
(Bitbake rev: b3d97130e1e70fe969399277dcd7cccd888103d6)
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>