i965: Delete pending CCS and HiZ ops in intel_miptree_make_shareable()

i965: Delete pending CCS and HiZ ops in intel_miptree_make_shareable()

Fixes crash in piglit
`egl_khr_gl_renderbuffer_image-clear-shared-image GL_DEPTH_COMPONENT24`
on Skylake.

The crash happened because blorp attempted to execute a pending hiz
clear after the hiz buffer was deleted. Deleting the pending hiz ops
when the hiz buffer gets deleted fixes the crash.

For good measure, this patch also deletes all pending CCS/MCS ops when
the CCS/MCS buffer gets deleted. I'm now aware of any bugs
caused by the dangling ops, but deleting them is clearly the right thing
to do.

Cc: Ben Widawsky <ben@bwidawsk.net>
Reviewed-by: Jason Ekstrand <jason@jlekstrand.net>
Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=99265