nx2: leave unwritten sparse blocks without memory when they get zeros

Title 1 clears about 1 GB of its sparse regions at boot through the GPU
memory manager. Every block the clear touched got 4 MiB of guest memory,
which the clear itself then committed on the host, and counted as written,
so the texture cache gave the images over it device memory too. A block
nobody wrote reads zero already: when the part of a write that lands on
it is all zero, leave it as it is.

(cherry picked from commit 0d7ff63fd1a373cecff6ba91022c9027e801e53f)

0 files changed, 0 insertions, 0 deletions