Make StreamAsynchronousIO an unique_ptr instead of a shared_ptr. I tried
passing the class by value, but the llvm::raw_ostream forwarder stored
in the Stream parent class isn't movable and I don't think it's worth
changing that. Additionally, there's a few places that expect a
StreamSP, which are easily created from a StreamUP.

This patch improves the synchronization of the debugger's output and error
streams using two new abstractions: `LockableStreamFile` and
`LockedStreamFile`.

 - `LockableStreamFile` is a wrapper around a `StreamFile` and a mutex. Client
   cannot use the `StreamFile` without calling `Lock`, which returns a
   `LockedStreamFile`.

 - `LockedStreamFile` is an RAII object that locks the stream for the duration
   of its existence.  As long as you hold on to the returned object you are
   permitted to write to the stream. The destruction of the object
   automatically flush the output stream.

In a later commit, I want to add a method to access diagnostics as
actual structured data, which will make these function names rather
confusing.

If your arguments or option values are of a type that naturally uses one
of our common completion mechanisms, you will get completion for free.
But if you have your own custom values or if you want to do fancy things
like have `break set -s foo.dylib -n ba<TAB>` only complete on symbols
in foo.dylib, you can use this new mechanism to achieve that.

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 patch is a follow-up to #97263 that fix ambigous abbreviated
command resolution.

When multiple commands are resolved, instead of failing to pick a
command to
run, this patch changes to resolution logic to check if there is a
single
alias match and if so, it will run the alias instead of the other
matches.

This has as a side-effect that we don't need to make aliases for every
substring of aliases to support abbrivated alias resolution.

Signed-off-by: Med Ismail Bennani <ismail@bennani.ma>

Among other things, returning an empty string as the repeat command
disables auto-repeat, which can be useful for state-changing commands.

There's one remaining refinement to this setup, which is that for parsed
script commands, it should be possible to change an option value, or add
a new option value that wasn't originally specified, then ask lldb "make
this back into a command string". That would make doing fancy things
with repeat commands easier.

That capability isn't present in the lldb_private side either, however.
So that's for a next iteration.

I haven't added this to the docs on adding commands yet. I wanted to
make sure this was an acceptable approach before I spend the time to do
that.

Partly, there's just a lot of unnecessary boiler plate. It's also
possible to define combinations of arguments that make no sense (e.g.
eArgRepeatPlus followed by eArgRepeatPlain...) but these are never
checked since we just push_back directly into the argument definitions.

This commit is step 1 of this cleanup - do the obvious stuff. In it, all
the simple homogenous argument lists and the breakpoint/watchpoint
ID/Range types, are set with common functions. This is an NFC change, it
just centralizes boiler plate. There's no checking yet because you can't
get a single argument wrong.

The end goal is that all argument definition goes through functions and
m_arguments is hidden so that you can't define inconsistent argument
sets.