we already check for `platform_sp` not null in one line below. 

existing code
```
if (platform_sp) {
      Status error;
      if (platform_sp) {
...
...
     }
}
```

`platform_sp` null check is redundant and error variable is unused. 

### TEST PLAN 
manual test 

```
satyajanga@devvm21837:toolchain $ ./bin/lldb
LLDB logging initialized. Logs stored in: /tmp
(lldb) platform select host
  Platform: host
    Triple: x86_64-*-linux-gnu
OS Version: 6.9.0 (6.9.0-0_fbk5_hardened_1_gf368ae920c1a)
  Hostname: 127.0.0.1
WorkingDir: /home/satyajanga/llvm-sand/build/Debug/fbcode-x86_64/toolchain
    Kernel: #1 SMP Tue Feb 11 07:24:41 PST 2025
    Kernel: Linux
   Release: 6.9.0-0_fbk5_hardened_1_gf368ae920c1a
   Version: #1 SMP Tue Feb 11 07:24:41 PST 2025
(lldb) platform process list
144 matching processes were found on "host"

PID    PARENT USER       TRIPLE                         NAME
====== ====== ========== ============================== ============================
130461 874915 satyajanga x86_64-*-linux-gnu             sushd
135505 874915 satyajanga x86_64-*-linux-gnu             hg.real
817146 874915 satyajanga x86_64-*-linux-gnu             vscode-thrift
874915 1      satyajanga                                
874947 874915 satyajanga                                
```

and running the existing tests
```
satyajanga@devvm21837:toolchain $ ./bin/llvm-lit -v  ~/llvm-sand/external/llvm-project/lldb/test/API/commands/platform/
-- Testing: 9 tests, 9 workers --
PASS: lldb-api :: commands/platform/file/read/TestPlatformFileRead.py (1 of 9)
PASS: lldb-api :: commands/platform/file/close/TestPlatformFileClose.py (2 of 9)
UNSUPPORTED: lldb-api :: commands/platform/sdk/TestPlatformSDK.py (3 of 9)
PASS: lldb-api :: commands/platform/basic/TestPlatformPython.py (4 of 9)
PASS: lldb-api :: commands/platform/basic/TestPlatformCommand.py (5 of 9)
PASS: lldb-api :: commands/platform/connect/TestPlatformConnect.py (6 of 9)
PASS: lldb-api :: commands/platform/process/launch/TestPlatformProcessLaunch.py (7 of 9)
PASS: lldb-api :: commands/platform/launchgdbserver/TestPlatformLaunchGDBServer.py (8 of 9)
PASS: lldb-api :: commands/platform/process/list/TestProcessList.py (9 of 9)

Testing Time: 13.48s

Total Discovered Tests: 9
  Unsupported: 1 (11.11%)
  Passed     : 8 (88.89%)
satyajanga@devvm21837:toolchain $ 
```

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.

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.

This is a follow-on to:

https://github.com/llvm/llvm-project/pull/82085

The completer for register names was missing from the argument table. I
somehow missed that the only register completer test was x86_64, so that
test broke.

I added the completer in to the right slot in the argument table, and
added a small completions test that just uses the alias register names.
If we end up having a platform that doesn't define register names, we'll
have to skip this test there, but it should add a sniff test for
register completion that will run most everywhere.

This reverts commit 21631494b068d9364b8dc8f18e59adee9131a0a5.

Reverted because of greendragon failure:

******************** TEST 'lldb-api :: functionalities/completion/TestCompletion.py' FAILED ********************
Script:

Most commands were adding argument completion handling by themselves,
resulting in a lot of unnecessary boilerplate. In many cases, this could
be done generically given the argument definition and the entries in the
g_argument_table.

I'm going to address this in a couple passes. In this first pass, I
added handling of commands that have only one argument list, with one
argument type, either single or repeated, and changed all the commands
that are of this sort (and don't have other bits of business in their
completers.)

I also added some missing connections between arg types and completions
to the table, and added a RemoteFilename and RemotePath to use in places
where we were using the Remote completers. Those arguments used to say
they were "files" but they were in fact remote files.

I also added a module arg type to use where we were using the module
completer. In that case, we should call the argument module.

[lldb] Part 2 of 2 - Refactor `CommandObject::DoExecute(...)` to return
`void` instead of ~~`bool`~~

Justifications:
- The code doesn't ultimately apply the `true`/`false` return values.
- The methods already pass around a `CommandReturnObject`, typically
with a `result` parameter.
- Each command return object already contains:
	- A more precise status
	- The error code(s) that apply to that status

Part 1 refactors the `CommandObject::Execute(...)` method.
- See
[https://github.com/llvm/llvm-project/pull/69989](https://github.com/llvm/llvm-project/pull/69989)

rdar://117378957

This reverts commit 3254623d73fb7252385817d8057640c9d5d5ffd1.

One test has been updated to add the "-s" flag which along with
86fd957af981f146a306831608d7ad2de65b9560 should fix the tests on MacOS.

An assert on hijack listener added in that patch was removed, it seems
to be correct on MacOS but not on Linux.

Fix `platform process launch` on macOS where it fails for lack of auto-resuming support.

This change reproduces the resuming logic found in `Target::Launch`.

This issue was identified by @DavidSpickett in D153636. This change relies on the tests
added in that PR. Thanks David.

Differential Revision: https://reviews.llvm.org/D153922

This reverts commit cc0fc358540517a3d205243c27bd543afeae2b02 due to a failure
reported on MacOS.