Add bitflags

Cargo.lock

@@ -1931,6 +1931,7 @@ name = "rustpython-codegen"
 version = "0.1.2"
 dependencies = [
  "ahash",
+ "bitflags",
  "indexmap",
  "insta",
  "itertools",

compiler/codegen/Cargo.toml

@@ -12,6 +12,7 @@ rustpython-ast = { path = "../ast", features = ["unparse"] }
 rustpython-compiler-core = { path = "../core", version = "0.1.1" }
 
 ahash = "0.7.6"
+bitflags = "1.3.2"
 indexmap = "1.8.1"
 itertools = "0.10.3"
 log = "0.4.16"