Flatten directory structure for cranelift_codegen_meta::isa

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

@@ -0,0 +1,18 @@
+use crate::cdsl::isa::TargetIsa;
+use crate::cdsl::settings::{SettingGroup, SettingGroupBuilder};
+
+use crate::shared::Definitions as SharedDefinitions;
+
+fn define_settings(_shared: &SettingGroup) -> SettingGroup {
+    let mut setting = SettingGroupBuilder::new("arm64");
+    let has_lse = setting.add_bool("has_lse", "Has Large System Extensions support.", "", false);
+
+    setting.add_predicate("use_lse", predicate!(has_lse));
+    setting.build()
+}
+
+pub(crate) fn define(shared_defs: &mut SharedDefinitions) -> TargetIsa {
+    let settings = define_settings(&shared_defs.settings);
+
+    TargetIsa::new("arm64", settings)
+}