add as_ptr to trait AllocBytes, fix 2 impls; add pub fn get_bytes_unchecked_raw in allocation.rs; add pub fn get_alloc_bytes_unchecked_raw[_mut] in memory.rs

Author: Strophox

src/alloc_bytes.rs

@@ -108,4 +108,8 @@ impl AllocBytes for MiriAllocBytes {
     fn as_mut_ptr(&mut self) -> *mut u8 {
         self.ptr
     }
+
+    fn as_ptr(&self) -> *const u8 {
+        self.ptr
+    }
 }