Merge pull request #3596 from marxin/add-malloc_stats

Add glibc's function: malloc_stats

Author: JohnTitor

libc-test/semver/linux-gnu.txt

@@ -643,6 +643,7 @@ lio_listio
 mallinfo
 mallinfo2
 malloc_info
+malloc_stats
 malloc_trim
 malloc_usable_size
 mallopt

src/unix/linux_like/linux/gnu/mod.rs

@@ -1426,6 +1426,7 @@ extern "C" {
     pub fn pthread_sigqueue(thread: ::pthread_t, sig: ::c_int, value: ::sigval) -> ::c_int;
     pub fn mallinfo() -> ::mallinfo;
     pub fn mallinfo2() -> ::mallinfo2;
+    pub fn malloc_stats();
     pub fn malloc_info(options: ::c_int, stream: *mut ::FILE) -> ::c_int;
     pub fn malloc_usable_size(ptr: *mut ::c_void) -> ::size_t;
     pub fn getpwent_r(