Currently, I am trying to port jemalloc to musl, I have found a issue "the return value of pthread_getspecific is not correct". The reasons are as follows:
1, Jemalloc uses pthread_key_t to implement cache feature, if codes call malloc, pthread_create_key will called and tsd will be initizlized.
2, Musl calls malloc before updating TLS size in dl stage 3.
3, New created initial_tls doesn't carry builtin_tls's tsd.


The attached patch could fix this issue, please review it, thanks.