Kernel: Verify interrupts are disabled when interacting with Mutexes

This should help prevent deadlocks where a thread blocks on a Mutex
while interrupts are disabled, and makes it impossible for the holder of
the Mutex to make forward progress because it cannot be scheduled in.

Hide it behind a new debug macro LOCK_IN_CRITICAL_DEBUG for now, because
Ext2FS takes a series of Mutexes from the page fault handler, which
executes with interrupts disabled.

Meta/CMake/all_the_debug_macros.cmake

@@ -101,6 +101,7 @@ set(LEXER_DEBUG ON)
 set(LINE_EDITOR_DEBUG ON)
 set(LOCAL_SOCKET_DEBUG ON)
 set(LOCK_DEBUG ON)
+set(LOCK_IN_CRITICAL_DEBUG ON)
 set(LOCK_RESTORE_DEBUG ON)
 set(LOCK_TRACE_DEBUG ON)
 set(LOOKUPSERVER_DEBUG ON)