Allow inlining for Atomic*::from_ptr

Currently this cannot be inlined, which among other things means it
can't be used in `compiler-builtins` [1]. These are trivial functions
that should be inlineable, so add `#[inline]`.

[1]: rust-lang/compiler-builtins#790 (comment)

(cherry picked from commit eb2a2f8)

Author: tgross35

library/core/src/sync/atomic.rs

@@ -469,6 +469,7 @@ impl AtomicBool {
     ///
     /// [valid]: crate::ptr#safety
     /// [Memory model for atomic accesses]: self#memory-model-for-atomic-accesses
+    #[inline]
     #[stable(feature = "atomic_from_ptr", since = "1.75.0")]
     #[rustc_const_stable(feature = "const_atomic_from_ptr", since = "1.84.0")]
     pub const unsafe fn from_ptr<'a>(ptr: *mut bool) -> &'a AtomicBool {
@@ -1389,6 +1390,7 @@ impl<T> AtomicPtr<T> {
     ///
     /// [valid]: crate::ptr#safety
     /// [Memory model for atomic accesses]: self#memory-model-for-atomic-accesses
+    #[inline]
     #[stable(feature = "atomic_from_ptr", since = "1.75.0")]
     #[rustc_const_stable(feature = "const_atomic_from_ptr", since = "1.84.0")]
     pub const unsafe fn from_ptr<'a>(ptr: *mut *mut T) -> &'a AtomicPtr<T> {
@@ -2525,6 +2527,7 @@ macro_rules! atomic_int {
             ///
             /// [valid]: crate::ptr#safety
             /// [Memory model for atomic accesses]: self#memory-model-for-atomic-accesses
+            #[inline]
             #[stable(feature = "atomic_from_ptr", since = "1.75.0")]
             #[rustc_const_stable(feature = "const_atomic_from_ptr", since = "1.84.0")]
             pub const unsafe fn from_ptr<'a>(ptr: *mut $int_type) -> &'a $atomic_type {