LibC: Implement pthread cancelation

This code is not tested at all but it looks correct xD

userspace/libraries/LibC/sys/socket.cpp

@@ -1,14 +1,17 @@
+#include <pthread.h>
 #include <sys/socket.h>
 #include <sys/syscall.h>
 #include <unistd.h>
 
 int accept(int socket, struct sockaddr* __restrict address, socklen_t* __restrict address_len)
 {
+	pthread_testcancel();
 	return accept4(socket, address, address_len, 0);
 }
 
 int accept4(int socket, struct sockaddr* __restrict address, socklen_t* __restrict address_len, int flags)
 {
+	pthread_testcancel();
 	return syscall(SYS_ACCEPT, socket, address, address_len, flags);
 }
 
@@ -19,6 +22,7 @@ int bind(int socket, const struct sockaddr* address, socklen_t address_len)
 
 int connect(int socket, const struct sockaddr* address, socklen_t address_len)
 {
+	pthread_testcancel();
 	return syscall(SYS_CONNECT, socket, address, address_len);
 }
 
@@ -29,11 +33,13 @@ int listen(int socket, int backlog)
 
 ssize_t recv(int socket, void* __restrict buffer, size_t length, int flags)
 {
+	pthread_testcancel();
 	return recvfrom(socket, buffer, length, flags, nullptr, nullptr);
 }
 
 ssize_t recvfrom(int socket, void* __restrict buffer, size_t length, int flags, struct sockaddr* __restrict address, socklen_t* __restrict address_len)
 {
+	pthread_testcancel();
 	sys_recvfrom_t arguments {
 		.socket = socket,
 		.buffer = buffer,
@@ -47,11 +53,13 @@ ssize_t recvfrom(int socket, void* __restrict buffer, size_t length, int flags,
 
 ssize_t send(int socket, const void* message, size_t length, int flags)
 {
+	pthread_testcancel();
 	return sendto(socket, message, length, flags, nullptr, 0);
 }
 
 ssize_t sendto(int socket, const void* message, size_t length, int flags, const struct sockaddr* dest_addr, socklen_t dest_len)
 {
+	pthread_testcancel();
 	sys_sendto_t arguments {
 		.socket = socket,
 		.message = message,