Change gating for outline atomic symbols in compiler-builtins and std

Build outline atomic symbols and enable the startup code whenever std is
built with `outline-atomics`, rather than only on Linux.  Since this is
no longer Linux-specific, also rename the `compiler-builtins` module.

Author: tgross35

library/compiler-builtins/compiler-builtins/src/aarch64_linux.rs renamed to library/compiler-builtins/compiler-builtins/src/aarch64_outline_atomics.rs

@@ -196,7 +196,7 @@ macro_rules! compare_and_swap {
                     "cbnz   w17, 0b",
                     "1:",
                     "ret",
-                    have_lse = sym crate::aarch64_linux::HAVE_LSE_ATOMICS,
+                    have_lse = sym crate::aarch64_outline_atomics::HAVE_LSE_ATOMICS,
                 }
             }
         }
@@ -228,7 +228,7 @@ macro_rules! compare_and_swap_i128 {
                     "cbnz   w15, 0b",
                     "1:",
                     "ret",
-                    have_lse = sym crate::aarch64_linux::HAVE_LSE_ATOMICS,
+                    have_lse = sym crate::aarch64_outline_atomics::HAVE_LSE_ATOMICS,
                 }
             }
         }
@@ -256,7 +256,7 @@ macro_rules! swap {
                     concat!(stxr!($ordering, $bytes), " w17, ", reg!($bytes, 16), ", [x1]"),
                     "cbnz   w17, 0b",
                     "ret",
-                    have_lse = sym crate::aarch64_linux::HAVE_LSE_ATOMICS,
+                    have_lse = sym crate::aarch64_outline_atomics::HAVE_LSE_ATOMICS,
                 }
             }
         }
@@ -286,7 +286,7 @@ macro_rules! fetch_op {
                     concat!(stxr!($ordering, $bytes), " w15, ", reg!($bytes, 17), ", [x1]"),
                     "cbnz  w15, 0b",
                     "ret",
-                    have_lse = sym crate::aarch64_linux::HAVE_LSE_ATOMICS,
+                    have_lse = sym crate::aarch64_outline_atomics::HAVE_LSE_ATOMICS,
                 }
             }
         }

library/compiler-builtins/compiler-builtins/src/lib.rs

@@ -56,8 +56,8 @@ pub mod arm;
 #[cfg(any(target_arch = "aarch64", target_arch = "arm64ec"))]
 pub mod aarch64;
 
-#[cfg(all(target_arch = "aarch64", target_os = "linux"))]
-pub mod aarch64_linux;
+#[cfg(all(target_arch = "aarch64", target_feature = "outline-atomics"))]
+pub mod aarch64_outline_atomics;
 
 #[cfg(all(
     kernel_user_helpers,

library/std/src/sys/configure_builtins.rs

@@ -1,6 +1,10 @@
 /// Hook into .init_array to enable LSE atomic operations at startup, if
 /// supported.
-#[cfg(all(target_arch = "aarch64", target_os = "linux", not(feature = "compiler-builtins-c")))]
+#[cfg(all(
+    target_arch = "aarch64",
+    target_feature = "outline-atomics",
+    not(feature = "compiler-builtins-c")
+))]
 #[used]
 #[unsafe(link_section = ".init_array.90")]
 static RUST_LSE_INIT: extern "C" fn() = {