Fix memory corruption when trying to get "core show locks".

Review https://reviewboard.asterisk.org/r/2580/ tried to fix the mismatch
in memory pools but had a math error determining the buffer size and
didn't address other similar memory pool mismatches.

* Effectively reverted the previous patch to go in the same direction as
trunk for the returned memory pool of ast_bt_get_symbols().

* Fixed memory leak in ast_bt_get_symbols() when BETTER_BACKTRACES is
defined.

* Fixed some formatting in ast_bt_get_symbols().

* Fixed sig_pri.c freeing memory allocated by libpri when MALLOC_DEBUG is
enabled.

* Fixed __dump_backtrace() freeing memory from ast_bt_get_symbols() when
MALLOC_DEBUG is enabled.

* Moved __dump_backtrace() because of compile issues with the utils
directory.

(closes issue ASTERISK-22221)
Reported by: Matt Jordan

Review: https://reviewboard.asterisk.org/r/2778/
........

Merged revisions 397525 from http://svn.asterisk.org/svn/asterisk/branches/1.8


git-svn-id: https://origsvn.digium.com/svn/asterisk/branches/11@397528 65c4cc65-6c06-0410-ace0-fbb531ad65f3

main/astmm.c

@@ -157,6 +157,31 @@ AST_MUTEX_DEFINE_STATIC_NOTRACKING(reglock);
 		}                                    \
 	} while (0)
 
+void *ast_std_malloc(size_t size)
+{
+	return malloc(size);
+}
+
+void *ast_std_calloc(size_t nmemb, size_t size)
+{
+	return calloc(nmemb, size);
+}
+
+void *ast_std_realloc(void *ptr, size_t size)
+{
+	return realloc(ptr, size);
+}
+
+void ast_std_free(void *ptr)
+{
+	free(ptr);
+}
+
+void ast_free_ptr(void *ptr)
+{
+	ast_free(ptr);
+}
+
 /*!
  * \internal
  *