Merge pull request #69 from SirJosh3917/patch-1

Mark `libmimalloc_sys` as `no_std` to support `no_std` users.

Author: octavonce

libmimalloc-sys/src/lib.rs

@@ -1,3 +1,4 @@
+#![no_std]
 // Copyright 2019 Octavian Oncescu
 
 use core::ffi::c_void;