feat: remove ptr_metadata to remove all nightly feature (#16)

Signed-off-by: Woshiluo Luo <woshiluo.luo@outlook.com>

Author: woshiluo

src/de.rs

@@ -78,7 +78,8 @@ where
 
         let total_size = u32::from_be(header.total_size);
         let raw_data_len = (total_size - HEADER_LEN) as usize;
-        let ans_ptr = core::ptr::from_raw_parts(ptr, raw_data_len);
+        let ans_ptr = core::ptr::slice_from_raw_parts(ptr, raw_data_len);
+        let ans_ptr = ans_ptr as *const DeviceTree;
         let device_tree: &DeviceTree = &*ans_ptr;
         let tags = device_tree.tags();
         let mut d = Deserializer {

src/lib.rs

@@ -12,7 +12,6 @@
 //! one with no-std support,
 //! the other one doesn't even need alloc.
 
-#![feature(ptr_metadata)]
 #![cfg_attr(not(feature = "std"), no_std)]
 
 #[cfg(feature = "alloc")]