kernel: Move some source files around.

* stack_protector.cpp now lives with other files in "lib".

 * Notifications.cpp, wait_for_objects.cpp go to a new "events" directory,
   which will soon contain more files related to the event_queue.

No functional change.

src/system/kernel/Jamfile

@@ -10,6 +10,7 @@ SubDir HAIKU_TOP src system kernel ;
 	SubDirC++Flags $(defines) ;
 }
 
+SEARCH_SOURCE += [ FDirName $(SUBDIR) events ] ;
 SEARCH_SOURCE += [ FDirName $(SUBDIR) locks ] ;
 SEARCH_SOURCE += [ FDirName $(SUBDIR) scheduler ] ;
 
@@ -41,13 +42,11 @@ KernelMergeObject kernel_core.o :
 	low_resource_manager.cpp
 	main.cpp
 	module.cpp
-	Notifications.cpp
 	port.cpp
 	real_time_clock.cpp
 	sem.cpp
 	shutdown.cpp
 	signal.cpp
-	stack_protector.cpp
 	system_info.cpp
 	smp.cpp
 	syscalls.cpp
@@ -57,7 +56,10 @@ KernelMergeObject kernel_core.o :
 	UserEvent.cpp
 	usergroup.cpp
 	UserTimer.cpp
+
+	# events
 	wait_for_objects.cpp
+	Notifications.cpp
 
 	# locks
 	lock.cpp

src/system/kernel/lib/Jamfile

@@ -59,8 +59,11 @@ SourceHdrs $(muslSources) :
 	[ FDirName $(posixSources) musl arch $(TARGET_KERNEL_ARCH_DIR) ] ;
 
 KernelMergeObject kernel_lib_posix.o :
-	# main
 	kernel_errno.cpp
+	kernel_vsprintf.cpp
+	stack_protector.cpp
+
+	# main
 	dirent.cpp
 	fcntl.cpp
 	poll.cpp
@@ -71,8 +74,6 @@ KernelMergeObject kernel_lib_posix.o :
 	ctype.cpp
 	localeconv.cpp
 	LocaleData.cpp
-	# stdio (this subdir)
-	kernel_vsprintf.cpp
 	# stdlib
 	abs.c
 	atoi.c