xfs : version 5 superblock, checksum header file

- Implemented version 5 superblock fields and necessary macros.

- Checksum functions are implemented which will be used for crc verification and crc updates.

- fssh_kernal_priv.h ROUNDDOWN macro definition is consistent with kernal.h definition.

Change-Id: I49b7c939bfd3ea1bffc85b3db42bc678dcce75cd
Reviewed-on: https://review.haiku-os.org/c/haiku/+/5350
Tested-by: Commit checker robot <no-reply+buildbot@haiku-os.org>
Reviewed-by: Adrien Destugues <pulkomandy@pulkomandy.tk>

xfs : Enabling -Werror and fixing all build issues that result

This patch will fix almost all warnings we have in xfs code.
There are some which I haven't fixed yet, I added comments on
part of code which is giving error and its type as well.

I tested all the changes on xfs_shell and everything is
working fine.

Change-Id: I1af1d09e7eab7f2c2397193bd5a584c5d40c424c
Reviewed-on: https://review.haiku-os.org/c/haiku/+/5257
Tested-by: Commit checker robot <no-reply+buildbot@haiku-os.org>
Reviewed-by: Adrien Destugues <pulkomandy@gmail.com>

xfs: Implemented reading of B+Tree based files

This patch adds the functionality to read B+Trees based files.
It shares similarity with extent based file reading functionality. Just
the way the extents are read is different.

Change-Id: I9b7ebe20171a8860fdc35024f7018540248aed61
Reviewed-on: https://review.haiku-os.org/c/haiku/+/3170
Tested-by: Commit checker robot <no-reply+buildbot@haiku-os.org>
Reviewed-by: Adrien Destugues <pulkomandy@gmail.com>

xfs: An attempt to read block directories

Map entries can be read, most structures are in place. Next is to
actually work with the directory block.

Change-Id: I700ee2e003bdef97838b1f06a95e53a5e4293658
Reviewed-on: https://review.haiku-os.org/c/haiku/+/2981
Reviewed-by: Adrien Destugues <pulkomandy@gmail.com>

xfs: Init AG Free Space Management

Currently need to make the B+Tree for AG Free Space Management.
The functions or the code for this task isn't complete. Sharing for
reference.

Change-Id: I1e29832b9645bd527962128a8c85b7ca24c7fd50
Reviewed-on: https://review.haiku-os.org/c/haiku/+/2378
Reviewed-by: Adrien Destugues <pulkomandy@gmail.com>

Adding superblock, types, xfs_mount and volume

Superblock work is done. A valid superblock is now detected.
xfs_shell will fail though, because the filesystem does not own it's
root node.

Change-Id: I78e3c21c4d0dd8e535fd24df4a0c107ed5fb201c
Reviewed-on: https://review.haiku-os.org/c/haiku/+/2286
Reviewed-by: Adrien Destugues <pulkomandy@gmail.com>