Kernel: Generate a coredump file when a process crashes

When a process crashes, we generate a coredump file and write it in
/tmp/coredumps/.

The coredump file is an ELF file of type ET_CORE.
It contains a segment for every userspace memory region of the process,
and an additional PT_NOTE segment that contains the registers state for
each thread, and a additional data about memory regions
(e.g their name).

Kernel/CMakeLists.txt

@@ -16,6 +16,7 @@ set(KERNEL_SOURCES
     CMOS.cpp
     CommandLine.cpp
     Console.cpp
+    CoreDump.cpp
     Devices/AsyncDeviceRequest.cpp
     Devices/BXVGADevice.cpp
     Devices/BlockDevice.cpp