nvc0/ir: Initialize Limits members in constructor.

Fix defect reported by Coverity Scan.

Uninitialized scalar field (UNINIT_CTOR)
uninit_member: Non-static class member min is not initialized in this constructor nor in any functions that it calls.
uninit_member: Non-static class member max is not initialized in this constructor nor in any functions that it calls.

Signed-off-by: Vinson Lee <vlee@freedesktop.org>
Reviewed-by: Karol Herbst <kherbst@redhat.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/11351>

src/gallium/drivers/nouveau/codegen/nv50_ir_lowering_nvc0.h

@@ -100,7 +100,7 @@ private:
    };
    struct Limits
    {
-      Limits() { }
+      Limits() : min(0), max(0) { }
       Limits(int min, int max) : min(min), max(max) { }
       int min, max;
    };