Userland: Add a helpful little program for provoking different crashes.

Currently supported crash types:

    -s : Segmentation violation
    -d : Division by zero
    -i : Illegal instruction
    -a : Abort

Userland/crash.cpp

@@ -0,0 +1,55 @@
+#include <AK/AKString.h>
+#include <stdio.h>
+#include <stdlib.h>
+
+static void print_usage_and_exit()
+{
+    printf("usage: crash -[sdia]\n");
+    exit(0);
+}
+
+int main(int argc, char** argv)
+{
+    enum Mode { SegmentationViolation, DivisionByZero, IllegalInstruction, Abort };
+    Mode mode = SegmentationViolation;
+
+    if (argc != 2)
+        print_usage_and_exit();
+
+    if (String(argv[1]) == "-s")
+        mode = SegmentationViolation;
+    else if (String(argv[1]) == "-d")
+        mode = DivisionByZero;
+    else if (String(argv[1]) == "-i")
+        mode = IllegalInstruction;
+    else if (String(argv[1]) == "-a")
+        mode = Abort;
+    else
+        print_usage_and_exit();
+
+    if (mode == SegmentationViolation) {
+        volatile int* crashme = nullptr;
+        *crashme = 0xbeef;
+        ASSERT_NOT_REACHED();
+    }
+
+    if (mode == DivisionByZero) {
+        volatile int lala = 10;
+        volatile int zero = 0;
+        volatile int test = lala / zero;
+        ASSERT_NOT_REACHED();
+    }
+
+    if (mode == IllegalInstruction) {
+        asm volatile("ud2");
+        ASSERT_NOT_REACHED();
+    }
+
+    if (mode == Abort) {
+        abort();
+        ASSERT_NOT_REACHED();
+    }
+
+    ASSERT_NOT_REACHED();
+    return 0;
+}