moved crates in lib/ to src/, renamed crates, modified some files' text (#660)

moved crates in lib/ to src/, renamed crates, modified some files' text (#660)

cranelift/codegen/src/isa/arm64/settings.rs

@@ -0,0 +1,9 @@
+//! ARM64 Settings.
+
+use crate::settings::{self, detail, Builder};
+use core::fmt;
+
+// Include code generated by `cranelift-codegen/meta-python/gen_settings.py`. This file contains a public
+// `Flags` struct with an impl for all of the settings defined in
+// `cranelift-codegen/meta-python/isa/arm64/settings.py`.
+include!(concat!(env!("OUT_DIR"), "/settings-arm64.rs"));