xla

56733fbc - Make the pjrt gpu allocator configurable (#5759)

Make the pjrt gpu allocator configurable (#5759) * Make the pjrt gpu allocator configurable * the default value changed from 0.9 to 0.75 * return default GpuAllocatorConfig --------- Co-authored-by: wangang.wa <wangang.wa@alibaba-inc.com>