A few files of lldb dir & few other files had duplicate headers
included. This patch removes those redundancies.

---------

Co-authored-by: Akash Agrawal <akashag@qti.qualcomm.com>

This patch removes all of the Set.* methods from Status.

This cleanup is part of a series of patches that make it harder use the
anti-pattern of keeping a long-lives Status object around and updating
it while dropping any errors it contains on the floor.

This patch is largely NFC, the more interesting next steps this enables
is to:
1. remove Status.Clear()
2. assert that Status::operator=() never overwrites an error
3. remove Status::operator=()

Note that step (2) will bring 90% of the benefits for users, and step
(3) will dramatically clean up the error handling code in various
places. In the end my goal is to convert all APIs that are of the form

`    ResultTy DoFoo(Status& error)
`
to

`    llvm::Expected<ResultTy> DoFoo()
`
How to read this patch?

The interesting changes are in Status.h and Status.cpp, all other
changes are mostly

` perl -pi -e 's/\.SetErrorString/ = Status::FromErrorString/g' $(git
grep -l SetErrorString lldb/source)
`
plus the occasional manual cleanup.

This reverts commit 71c4d186f1cf247f1aa45f4fd1b38f350b68d123.
The reinterpret casts were not needed.

This reverts commit af38530ee29c285f3827e33a41edf27c9c3a6767 due
to a build failure on 32 bit.

So that there is only one function that NativeThreads call,
which takes a siginfo. Everything else is an internal detail.

Reviewed By: labath, JDevlieghere

Differential Revision: https://reviews.llvm.org/D146043

Fix ThreadStopInfo struct to include the signal number for all events.
Since signo was not included in the details for fork, vfork
and vforkdone stops, the code incidentally referenced the wrong union
member, resulting in wrong signo being sent.

Sponsored by: The FreeBSD Foundation
Differential Revision: https://reviews.llvm.org/D127193

Differential Revision: https://reviews.llvm.org/D100554

Copy the recent improvements from the FreeBSDRemote plugin, notably:

- moving event reporting setup into SetupTrace() helper

- adding more debug info into SIGTRAP handling

- handling user-generated (and unknown) SIGTRAP events

- adding missing error handling to the generic signal handler

- fixing attaching to processes

- switching watchpoint helpers to use llvm::Error

- minor style and formatting changes

This fixes a number of tests, mostly related to fixed attaching.

Differential Revision: https://reviews.llvm.org/D91167