!139 增加内核epoll系统调用适配musl接口并增加测试用例

Merge pull request !139 from wangchen/tocommit

porting/liteos_a/user/src/linux/epoll.c

-#include <sys/epoll.h>
-#include <signal.h>
-#include <errno.h>
-#include "syscall.h"
-#include <unsupported_api.h>
-
-int epoll_create(int size)
-{
-	unsupported_api(__FUNCTION__);
-	return epoll_create1(0);
-}
-
-int epoll_create1(int flags)
-{
-	int r = __syscall(SYS_epoll_create1, flags);
-#ifdef SYS_epoll_create
-	if (r==-ENOSYS && !flags) r = __syscall(SYS_epoll_create, 1);
-#endif
-	return __syscall_ret(r);
-}
-
-int epoll_ctl(int fd, int op, int fd2, struct epoll_event *ev)
-{
-	unsupported_api(__FUNCTION__);
-	return syscall(SYS_epoll_ctl, fd, op, fd2, ev);
-}
-
-int epoll_pwait(int fd, struct epoll_event *ev, int cnt, int to, const sigset_t *sigs)
-{
-	int r = __syscall(SYS_epoll_pwait, fd, ev, cnt, to, sigs, _NSIG/8);
-#ifdef SYS_epoll_wait
-	if (r==-ENOSYS && !sigs) r = __syscall(SYS_epoll_wait, fd, ev, cnt, to);
-#endif
-	return __syscall_ret(r);
-}
-
-int epoll_wait(int fd, struct epoll_event *ev, int cnt, int to)
-{
-	unsupported_api(__FUNCTION__);
-	return epoll_pwait(fd, ev, cnt, to, 0);
-}