Kernel: Add support for SA_SIGINFO

We currently don't really populate most of the fields, but that can
wait :^)

Kernel/API/POSIX/ucontext.h

@@ -0,0 +1,60 @@
+/*
+ * Copyright (c) 2022, Ali Mohammad Pur <mpfard@serenityos.org>
+ *
+ * SPDX-License-Identifier: BSD-2-Clause
+ */
+
+#pragma once
+
+#include <Kernel/API/POSIX/sys/types.h>
+#include <Kernel/Arch/mcontext.h>
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+typedef struct __mcontext mcontext_t;
+
+typedef struct __ucontext {
+    struct __ucontext* uc_link;
+    sigset_t uc_sigmask;
+    stack_t uc_stack;
+    mcontext_t uc_mcontext;
+} ucontext_t;
+
+#define ILL_ILLOPC 0
+#define ILL_ILLOPN 1
+#define ILL_ILLADR 2
+#define ILL_ILLTRP 3
+#define ILL_PRVOPC 4
+#define ILL_PRVREG 5
+#define ILL_COPROC 6
+#define ILL_BADSTK 7
+
+#define FPE_INTDIV 0
+#define FPE_INTOVF 1
+#define FPE_FLTDIV 2
+#define FPE_FLTOVF 3
+#define FPE_FLTUND 4
+#define FPE_FLTRES 5
+#define FPE_FLTINV 6
+
+#define SEGV_MAPERR 0
+#define SEGV_ACCERR 1
+
+#define BUS_ADRALN 0
+#define BUS_ADRERR 1
+#define BUS_OBJERR 2
+
+#define TRAP_BRKPT 0
+#define TRAP_TRACE 1
+
+#define SI_USER 0x40000000
+#define SI_QUEUE 0x40000001
+#define SI_TIMER 0x40000002
+#define SI_ASYNCIO 0x40000003
+#define SI_MESGQ 0x40000004
+
+#ifdef __cplusplus
+}
+#endif