LibC: Implement pthread cancelation

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

kernel/kernel/Process.cpp

@@ -351,8 +351,11 @@ namespace Kernel
 			.master_tls_addr = reinterpret_cast<void*>(master_addr),
 			.master_tls_size = master_size,
 			.cleanup_stack = nullptr,
-			.id = -1,
+			.id = 0,
 			.errno_ = 0,
+			.cancel_type = 0,
+			.cancel_state = 0,
+			.canceled = 0,
 		};
 		const uintptr_t dtv[2] { 1, region->vaddr() };
 

kernel/kernel/Thread.cpp

@@ -525,6 +525,8 @@ namespace Kernel
 				// Ignore the signal
 				case SIGCHLD:
 				case SIGURG:
+				case SIGWINCH:
+				case SIGCANCEL:
 					break;
 
 				// Stop the process: