Rollup merge of #154221 - DanielEScherzer:isize-lc, r=Mark-Simulacrum

`vec::as_mut_slice()`: use lowercase "isize" in safety comment

To match other references to that type

library/alloc/src/vec/mod.rs

@@ -1853,7 +1853,7 @@ pub const fn as_mut_slice(&mut self) -> &mut [T] {
         // SAFETY: `slice::from_raw_parts_mut` requires pointee is a contiguous, aligned buffer of
         // size `len` containing properly-initialized `T`s. Data must not be accessed through any
         // other pointer for the returned lifetime. Further, `len * size_of::<T>` <=
-        // `ISIZE::MAX` and allocation does not "wrap" through overflowing memory addresses.
+        // `isize::MAX` and allocation does not "wrap" through overflowing memory addresses.
         //
         // * Vec API guarantees that self.buf:
         //      * contains only properly-initialized items within 0..len