Lock dynasm to 0.1.1 and serde_derive 1.0.12 to compile against old rustc verions.
Lock dynasm to 0.1.1 and serde_derive 1.0.12 to compile against old rustc verions.

Both library depend on the ability to parse Rust syntax, which is
changing. However, HolyJit is currently stuck in the past until
rebased. This patch lock the version of dynasm and serde_derive to account
for this fact.

nbp/holyjit,nbp/holyjit