Kernel: Finalizer should not go back to sleep if there's more to do

Before putting itself back on the wait queue, the finalizer task will
now check if there's more work to do, and if so, do it first. :^)

This patch also puts a bunch of process/thread debug logging behind
PROCESS_DEBUG and THREAD_DEBUG since it was unbearable to debug this
stuff with all the spam.

Kernel/Process.cpp

@@ -73,6 +73,7 @@
 #include <LibC/signal_numbers.h>
 #include <LibELF/ELFLoader.h>
 
+//#define PROCESS_DEBUG
 //#define DEBUG_POLL_SELECT
 //#define DEBUG_IO
 //#define TASK_DEBUG
@@ -1295,7 +1296,9 @@ Process::Process(Thread*& first_thread, const String& name, uid_t uid, gid_t gid
     , m_tty(tty)
     , m_ppid(ppid)
 {
+#ifdef PROCESS_DEBUG
     dbg() << "Created new process " << m_name << "(" << m_pid << ")";
+#endif
 
     m_page_directory = PageDirectory::create_for_userspace(*this, fork_parent ? &fork_parent->page_directory().range_allocator() : nullptr);
 #ifdef MM_DEBUG
@@ -2278,7 +2281,9 @@ int Process::reap(Process& process)
             }
         }
 
+#ifdef PROCESS_DEBUG
         dbg() << "Reaping process " << process;
+#endif
         ASSERT(process.is_dead());
         g_processes->remove(&process);
     }
@@ -2289,7 +2294,10 @@ int Process::reap(Process& process)
 pid_t Process::sys$waitpid(pid_t waitee, int* wstatus, int options)
 {
     REQUIRE_PROMISE(stdio);
+
+#ifdef PROCESS_DEBUG
     dbg() << "sys$waitpid(" << waitee << ", " << wstatus << ", " << options << ")";
+#endif
 
     if (!options) {
         // FIXME: This can't be right.. can it? Figure out how this should actually work.
@@ -2928,7 +2936,9 @@ int Process::sys$chown(const Syscall::SC_chown_params* user_params)
 void Process::finalize()
 {
     ASSERT(current == g_finalizer);
+#ifdef PROCESS_DEBUG
     dbg() << "Finalizing process " << *this;
+#endif
 
     m_fds.clear();
     m_tty = nullptr;