treewide: Remove more is_ssa asserts

Stuff Coccinelle missed.

   sed -i -e '/assert(.*\.is_ssa)/d' $(git grep -l is_ssa)
   sed -i -e '/ASSERT.*\.is_ssa)/d' $(git grep -l is_ssa)

+ a manual fixup to restore the assert for parallel copy lowering.

Signed-off-by: Alyssa Rosenzweig <alyssa@rosenzweig.io>
Reviewed-by: Faith Ekstrand <faith.ekstrand@collabora.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/24432>

src/asahi/compiler/agx_compile.c

@@ -2088,7 +2088,6 @@ agx_lower_front_face(struct nir_builder *b, nir_instr *instr, UNUSED void *data)
    if (intr->intrinsic != nir_intrinsic_load_front_face)
       return false;
 
-   assert(intr->dest.is_ssa);
    nir_ssa_def *def = &intr->dest.ssa;
    assert(def->bit_size == 1);