message: adjust MemoryKind comment
diff: @@ -146,9 +146,7 @@ pub trait EvalContextExt<'mir, 'tcx: 'mir>: crate::MiriEvalContextExt<'mir, 'tcx
  }
  // Allocate environment block & Store environment variables to environment block.
  // Final null terminator(block terminator) is added by `alloc_os_str_to_wide_str`.
  - // FIXME: MemoryKind should be `MiMemoryKind::Machine`,
  - // but using it results in a Stacked Borrows error when running MIRI on 'tests/run-pass/env.rs'
  - // For now, use `MiriMemoryKind::WinHeap` instead.
  + // FIXME: MemoryKind should be `Machine`, blocked on https://github.com/rust-lang/rust/pull/70479.
  let envblock_ptr = this.alloc_os_str_as_wide_str(&env_vars, MiriMemoryKind::WinHeap.into());
  // If the function succeeds, the return value is a pointer to the environment block of the current process.
  Ok(envblock_ptr.into())
  @@ -160,9 +158,7 @@ pub trait EvalContextExt<'mir, 'tcx: 'mir>: crate::MiriEvalContextExt<'mir, 'tcx
  this.assert_target_os("windows", "FreeEnvironmentStringsW");
  let env_block_ptr = this.read_scalar(env_block_op)?.not_undef()?;
  - // FIXME: MemoryKind should be `MiMemoryKind::Machine`,
  - // but using it results in a Stacked Borrows error when running MIRI on 'tests/run-pass/env.rs'
  - // For now, use `MiriMemoryKind::WinHeap` instead.
  + // FIXME: MemoryKind should be `Machine`, blocked on https://github.com/rust-lang/rust/pull/70479.
  let result = this.memory.deallocate(this.force_ptr(env_block_ptr)?, None, MiriMemoryKind::WinHeap.into());
  // If the function succeeds, the return value is nonzero.
  Ok(result.is_ok() as i32)
  