Use direct pointers for Symbols

This relies on the extensions to Rust's `const`s described in issue
rust-lang/const-eval#11, and will not compile today.

Author: rpjohnst

gml/Cargo.toml

@@ -7,6 +7,7 @@ edition = "2018"
 [dependencies]
 gml-meta = { path = "meta" }
 project = { path = "../project" }
+quickdry = "0.1"
 
 [target.wasm32-unknown-unknown.dependencies]
 wasm-host = { path = "../wasm-host" }