fix-tests
[libc] Add implementation of POSIX lseek function.
[libc] Add dirent.h functions opendir, readdir, closedir and dirfd.
[libc] Add implementations of POSIX mkdir, mkdirat, rmdir, unlink and unlinkat.
[libc] Make the errno macro resolve to the thread local variable directly.
[libc][NFC] Make all top of file comments consistent.
[libc] Add scaffolding for ctype and implementation of isalpha
[libc] Add POSIX close, fsync, open, read and write functions.
[libc] Add simple x86_64 floating point exception and rounding mode support.
[libc] add inttypes header
[libc] Add a definition of pthread_attr_t and its getters and setters.
[libc] Move the remaining public types to their own type headers.
Initial commit of mktime.