Local Hint Resolve load_valid_access valid_access_load: mem.

Theorem load_cast:
forall m chunk b ofs v,
load chunk m b ofs = Some v ->
match chunk with
| Mint8signed => v = Val.sign_ext 8 v
| Mint8unsigned => v = Val.zero_ext 8 v
| Mint16signed => v = Val.sign_ext 16 v
| Mint16unsigned => v = Val.zero_ext 16 v
| _ => True
end.