Rollup merge of #118398 - mu001999:std/add_cfgs, r=thomcc

Add proper cfgs in std

Detected by #118257

library/alloc/src/alloc.rs

@@ -423,12 +423,14 @@ pub unsafe fn __rdl_oom(size: usize, _align: usize) -> ! {
     }
 }
 
+#[cfg(not(no_global_oom_handling))]
 /// Specialize clones into pre-allocated, uninitialized memory.
 /// Used by `Box::clone` and `Rc`/`Arc::make_mut`.
 pub(crate) trait WriteCloneIntoRaw: Sized {
     unsafe fn write_clone_into_raw(&self, target: *mut Self);
 }
 
+#[cfg(not(no_global_oom_handling))]
 impl<T: Clone> WriteCloneIntoRaw for T {
     #[inline]
     default unsafe fn write_clone_into_raw(&self, target: *mut Self) {
@@ -438,6 +440,7 @@ impl<T: Clone> WriteCloneIntoRaw for T {
     }
 }
 
+#[cfg(not(no_global_oom_handling))]
 impl<T: Copy> WriteCloneIntoRaw for T {
     #[inline]
     unsafe fn write_clone_into_raw(&self, target: *mut Self) {

library/alloc/src/collections/mod.rs

@@ -148,6 +148,7 @@ fn fmt(
 
 /// An intermediate trait for specialization of `Extend`.
 #[doc(hidden)]
+#[cfg(not(no_global_oom_handling))]
 trait SpecExtend<I: IntoIterator> {
     /// Extends `self` with the contents of the given iterator.
     fn spec_extend(&mut self, iter: I);

library/alloc/src/rc.rs

@@ -2023,6 +2023,7 @@ unsafe fn allocate_for_slice_in(len: usize, alloc: &A) -> *mut RcBox<[T]> {
     }
 }
 
+#[cfg(not(no_global_oom_handling))]
 /// Specialization trait used for `From<&[T]>`.
 trait RcFromSlice<T> {
     fn from_slice(slice: &[T]) -> Self;

library/alloc/src/sync.rs

@@ -3503,6 +3503,7 @@ fn from_iter<I: IntoIterator<Item = T>>(iter: I) -> Self {
     }
 }
 
+#[cfg(not(no_global_oom_handling))]
 /// Specialization trait used for collecting into `Arc<[T]>`.
 trait ToArcSlice<T>: Iterator<Item = T> + Sized {
     fn to_arc_slice(self) -> Arc<[T]>;

library/alloc/src/vec/mod.rs

@@ -58,6 +58,7 @@
 use core::cmp::Ordering;
 use core::fmt;
 use core::hash::{Hash, Hasher};
+#[cfg(not(no_global_oom_handling))]
 use core::iter;
 use core::marker::PhantomData;
 use core::mem::{self, ManuallyDrop, MaybeUninit, SizedTypeProperties};
@@ -101,6 +102,7 @@
 #[cfg(not(no_global_oom_handling))]
 use self::is_zero::IsZero;
 
+#[cfg(not(no_global_oom_handling))]
 mod is_zero;
 
 #[cfg(not(no_global_oom_handling))]
@@ -2599,6 +2601,7 @@ pub fn from_elem_in<T: Clone, A: Allocator>(elem: T, n: usize, alloc: A) -> Vec<
     <T as SpecFromElem>::from_elem(elem, n, alloc)
 }
 
+#[cfg(not(no_global_oom_handling))]
 trait ExtendFromWithinSpec {
     /// # Safety
     ///
@@ -2607,6 +2610,7 @@ trait ExtendFromWithinSpec {
     unsafe fn spec_extend_from_within(&mut self, src: Range<usize>);
 }
 
+#[cfg(not(no_global_oom_handling))]
 impl<T: Clone, A: Allocator> ExtendFromWithinSpec for Vec<T, A> {
     default unsafe fn spec_extend_from_within(&mut self, src: Range<usize>) {
         // SAFETY:
@@ -2626,6 +2630,7 @@ impl<T: Clone, A: Allocator> ExtendFromWithinSpec for Vec<T, A> {
     }
 }
 
+#[cfg(not(no_global_oom_handling))]
 impl<T: Copy, A: Allocator> ExtendFromWithinSpec for Vec<T, A> {
     unsafe fn spec_extend_from_within(&mut self, src: Range<usize>) {
         let count = src.len();