Update swc

Closes GH-57.

Reviewed-by: Titus Wormer <[email protected]>

Author: kdy1

Cargo.toml

@@ -18,7 +18,7 @@ serializable = ["serde"]
 [dependencies]
 markdown = "=1.0.0-alpha.21"
 serde = { version = "1", optional = true }
-swc_core = { version = "4.0", features = [
+swc_core = { version = "5", features = [
   "common",
   "ecma_ast",
   "ecma_codegen",