Remove Arc from environment::globals() (take 2)

We don't forward this variable for storage in any structs, so there's no reason
to go through an Arc instead of returning the `&'static EnvStack` directly.

NB: This particular change was safe, and passes all tests on its own.

src/bin/fish_indent.rs

@@ -990,7 +990,7 @@ fn throwing_main() -> i32 {
                 }
             }
             OutputType::Ansi => {
-                colored_output = colorize(&output_wtext, &colors, &**EnvStack::globals());
+                colored_output = colorize(&output_wtext, &colors, EnvStack::globals());
             }
             OutputType::Html => {
                 colored_output = html_colorize(&output_wtext, &colors);

src/complete.rs

@@ -2473,7 +2473,7 @@ pub fn complete_load(cmd: &wstr, parser: &Parser) -> bool {
     let path_to_load = completion_autoloader
         .lock()
         .expect("mutex poisoned")
-        .resolve_command(cmd, &**EnvStack::globals());
+        .resolve_command(cmd, EnvStack::globals());
     if let Some(path_to_load) = path_to_load {
         Autoload::perform_autoload(&path_to_load, parser);
         completion_autoloader

src/env/environment.rs

@@ -360,10 +360,10 @@ impl EnvStack {
 
     /// A variable stack that only represents globals.
     /// Do not push or pop from this.
-    pub fn globals() -> &'static Arc<EnvStack> {
+    pub fn globals() -> &'static EnvStack {
         use std::sync::OnceLock;
-        static GLOBALS: OnceLock<Arc<EnvStack>> = OnceLock::new();
-        &GLOBALS.get_or_init(|| Arc::new(EnvStack::new()))
+        static GLOBALS: OnceLock<EnvStack> = OnceLock::new();
+        GLOBALS.get_or_init(|| EnvStack::new())
     }
 
     /// Access the principal variable stack, associated with the principal parser.

src/function.rs

@@ -122,7 +122,7 @@ pub fn load(name: &wstr, parser: &Parser) -> bool {
         if funcset.allow_autoload(name) {
             if let Some(path) = funcset
                 .autoloader
-                .resolve_command(name, &**EnvStack::globals())
+                .resolve_command(name, EnvStack::globals())
             {
                 path_to_autoload = Some(path);
             }

src/operation_context.rs

@@ -65,7 +65,7 @@ impl<'a> OperationContext<'a> {
     // Return an operation context that contains only global variables, no parser, and never
     // cancels.
     pub fn globals() -> OperationContext<'static> {
-        OperationContext::background(&**EnvStack::globals(), EXPANSION_LIMIT_DEFAULT)
+        OperationContext::background(EnvStack::globals(), EXPANSION_LIMIT_DEFAULT)
     }
 
     /// Construct from a full set of properties.