ralloc: Hook up C++ destructors to ralloc when necessary.

ralloc: Hook up C++ destructors to ralloc when necessary.

This patch makes sure that class destructors are called as they should
be when a C++ object allocated by ralloc is released.

Based on a previous patch by Kenneth Graunke, but it doesn't exhibit
the ~0.8% performance regression in shader compilation times because
we now use the HAS_TRIVIAL_DESTRUCTOR() macro to detect the typical
case where the indirect function call can be avoided because the
object's destructor doesn't need to do anything.

Reviewed-by: Ian Romanick <ian.d.romanick@intel.com>