std::alloc: checking if the alignment is, at least, a word size.

so we do not error (at least on solarish systems) in that case.
close rust-langGH-124787

library/std/src/sys/pal/unix/alloc.rs

@@ -87,7 +87,11 @@ cfg_if::cfg_if! {
             // [3]: https://bugs.chromium.org/p/chromium/issues/detail?id=138579
             // [4]: https://chromium.googlesource.com/chromium/src/base/+/master/
             //                                       /memory/aligned_memory.cc
-            libc::memalign(layout.align(), layout.size()) as *mut u8
+            //
+            // We purpose use the higher alignment so we have it at least
+            // a proper word size value guaranteed.
+            let align = layout.align().max(create::mem::size_of::<usize>());
+            libc::memalign(align, layout.size()) as *mut u8
         }
     } else if #[cfg(target_os = "wasi")] {
         #[inline]