anv: Add another align_down helper

Reviewed-by: Lionel Landwerlin <lionel.g.landwerlin@intel.com>
Reviewed-by: Jordan Justen <jordan.l.justen@intel.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/merge_requests/3519>

src/intel/vulkan/anv_private.h

@@ -237,10 +237,16 @@ align_u32(uint32_t v, uint32_t a)
 }
 
 static inline uint64_t
-align_u64(uint64_t v, uint64_t a)
+align_down_u64(uint64_t v, uint64_t a)
 {
    assert(a != 0 && a == (a & -a));
-   return (v + a - 1) & ~(a - 1);
+   return v & ~(a - 1);
+}
+
+static inline uint64_t
+align_u64(uint64_t v, uint64_t a)
+{
+   return align_down_u64(v + a - 1, a);
 }
 
 static inline int32_t