Rollup merge of rust-lang#130549 - biabbas:riscv32_wrs_vxworks, r=nne…

…thercote

Add RISC-V vxworks targets

Risc-V 32 and RISC-V 64 targets are to be added in the target list.

std/src/sys/alloc/unix.rs

@@ -71,6 +71,7 @@ cfg_if::cfg_if! {
         }
     } else {
         #[inline]
+        #[cfg_attr(target_os = "vxworks", allow(unused_unsafe))]
         unsafe fn aligned_malloc(layout: &Layout) -> *mut u8 {
             let mut out = ptr::null_mut();
             // We prefer posix_memalign over aligned_alloc since it is more widely available, and