Add allocation functions

Author: EFanZh

library/alloc/src/lib.rs

@@ -110,6 +110,7 @@
 #![feature(deprecated_suggestion)]
 #![feature(deref_pure_trait)]
 #![feature(dispatch_from_dyn)]
+#![feature(drop_guard)]
 #![feature(ergonomic_clones)]
 #![feature(error_generic_member_access)]
 #![feature(exact_size_is_empty)]

library/alloc/src/raw_rc/mod.rs

@@ -63,7 +63,9 @@
 
 use core::cell::UnsafeCell;
 
+mod rc_alloc;
 mod rc_layout;
+mod rc_value_pointer;
 
 /// Stores reference counts.
 #[cfg_attr(target_pointer_width = "16", repr(C, align(2)))]