82c318224b
The `__GNUC__` is also available in `clang` as is just used to provide the major version of a GNU-C compatible compiler [[1]]. So I check for `tlsf` if the `alloc_size()` is available by using the combination of macros as proposed here: https://stackoverflow.com/a/43205345/395687 [1]: https://gcc.gnu.org/onlinedocs/cpp/Common-Predefined-Macros.html