Kernel: Implement sysconf(_SC_SYMLOOP_MAX)

Not much to say here, this is an implementation of this call that
accesses the actual limit constant that's used by the VirtualFileSystem
class.

As a side note, this is required for my eventual Qt port.

Kernel/API/POSIX/unistd.h

@@ -38,6 +38,7 @@ enum {
     _SC_PAGESIZE,
     _SC_GETPW_R_SIZE_MAX,
     _SC_CLK_TCK,
+    _SC_SYMLOOP_MAX,
 };
 
 #define _SC_MONOTONIC_CLOCK _SC_MONOTONIC_CLOCK
@@ -49,6 +50,7 @@ enum {
 #define _SC_TTY_NAME_MAX _SC_TTY_NAME_MAX
 #define _SC_GETPW_R_SIZE_MAX _SC_GETPW_R_SIZE_MAX
 #define _SC_CLK_TCK _SC_CLK_TCK
+#define _SC_SYMLOOP_MAX _SC_SYMLOOP_MAX
 
 #ifdef __cplusplus
 }

Kernel/Syscalls/sysconf.cpp

@@ -4,6 +4,7 @@
  * SPDX-License-Identifier: BSD-2-Clause
  */
 
+#include <Kernel/FileSystem/VirtualFileSystem.h>
 #include <Kernel/Process.h>
 #include <Kernel/Time/TimeManagement.h>
 
@@ -30,6 +31,8 @@ ErrorOr<FlatPtr> Process::sys$sysconf(int name)
         return 4096; // idk
     case _SC_CLK_TCK:
         return TimeManagement::the().ticks_per_second();
+    case _SC_SYMLOOP_MAX:
+        return Kernel::VirtualFileSystem::symlink_recursion_limit;
     default:
         return EINVAL;
     }