Kernel+LibC: Move name length constants to Kernel/API from limits.h

Reduce inclusion of limits.h as much as possible at the same time.

This does mean that kmalloc.h is now including Kernel/API/POSIX/limits.h
instead of LibC/limits.h, but the scope could be limited a lot more.
Basically every file in the kernel includes kmalloc.h, and needs the
limits.h include for PAGE_SIZE.

Kernel/API/InodeWatcherEvent.h

@@ -10,7 +10,7 @@
 #include <AK/Types.h>
 
 #ifdef KERNEL
-#    include <LibC/limits.h>
+#    include <Kernel/API/POSIX/sys/limits.h>
 #else
 #    include <limits.h>
 #endif

Kernel/API/POSIX/sys/limits.h

@@ -7,6 +7,22 @@
 
 #pragma once
 
+// FIXME: This file can be included from Lagom, but it should only be included on Serenity. When that is the case, we can remove the ifdef
+#ifndef PAGE_SIZE
+#    define PAGE_SIZE 4096
+#endif
+
+#define PATH_MAX 4096
+#if !defined MAXPATHLEN && defined PATH_MAX
+#    define MAXPATHLEN PATH_MAX
+#endif
+
+#define NAME_MAX 255
+
+#define HOST_NAME_MAX 64
+
+#define TTY_NAME_MAX 32
+
 #define NGROUPS_MAX 32
 
 #define PTHREAD_STACK_MIN (64 * 1024) // 64KiB

Kernel/Heap/kmalloc.h

@@ -7,7 +7,7 @@
 #pragma once
 
 #include <AK/Types.h>
-#include <LibC/limits.h>
+#include <Kernel/API/POSIX/sys/limits.h> // For PAGE_SIZE. Everyone needs PAGE_SIZE
 
 #define KMALLOC_SCRUB_BYTE 0xbb
 #define KFREE_SCRUB_BYTE 0xaa

Kernel/Memory/VirtualRange.cpp

@@ -8,7 +8,6 @@
 #include <AK/Vector.h>
 #include <Kernel/Memory/MemoryManager.h>
 #include <Kernel/Memory/VirtualRange.h>
-#include <LibC/limits.h>
 
 namespace Kernel::Memory {
 

Kernel/Process.cpp

@@ -18,6 +18,7 @@
 #    include <Kernel/Devices/KCOVDevice.h>
 #endif
 #include <Kernel/API/POSIX/errno.h>
+#include <Kernel/API/POSIX/sys/limits.h>
 #include <Kernel/Devices/NullDevice.h>
 #include <Kernel/FileSystem/Custody.h>
 #include <Kernel/FileSystem/OpenFileDescription.h>
@@ -38,7 +39,6 @@
 #include <Kernel/Thread.h>
 #include <Kernel/ThreadTracer.h>
 #include <Kernel/TimerQueue.h>
-#include <LibC/limits.h>
 
 namespace Kernel {
 

Kernel/Syscalls/execve.cpp

@@ -20,7 +20,6 @@
 #include <Kernel/Random.h>
 #include <Kernel/Scheduler.h>
 #include <Kernel/Time/TimeManagement.h>
-#include <LibC/limits.h>
 #include <LibELF/AuxiliaryVector.h>
 #include <LibELF/Image.h>
 #include <LibELF/Validation.h>

Kernel/Syscalls/mmap.cpp

@@ -20,7 +20,6 @@
 #include <Kernel/PerformanceEventBuffer.h>
 #include <Kernel/PerformanceManager.h>
 #include <Kernel/Process.h>
-#include <LibC/limits.h>
 #include <LibELF/Validation.h>
 
 namespace Kernel {

Userland/Libraries/LibC/limits.h

@@ -12,21 +12,6 @@
 #include <bits/stdint.h>
 #include <bits/wchar.h>
 
-#ifndef PAGE_SIZE
-#    define PAGE_SIZE 4096
-#endif
-
-#define HOST_NAME_MAX 64
-
-#define PATH_MAX 4096
-#if !defined MAXPATHLEN && defined PATH_MAX
-#    define MAXPATHLEN PATH_MAX
-#endif
-
-#define NAME_MAX 255
-
-#define TTY_NAME_MAX 32
-
 #define PIPE_BUF 4096
 
 #define INT_MAX INT32_MAX