This is an ongoing series of commits that are reformatting our Python
code. Reformatting is done with `black` (23.1.0).

If you end up having problems merging this commit because you have made
changes to a python file, the best way to handle that is to run `git
checkout --ours <yourfile>` and then reformat it with black.

RFC: https://discourse.llvm.org/t/rfc-document-and-standardize-python-code-style

Differential revision: https://reviews.llvm.org/D151460

This commit combines the initial commit (7c240de609af), a fix for x86_64 Linux
(3a0581501e76) and a fix for thinko in a last minute rewrite that I really
should have run the testsuite on.

Also, make sure that all the "I need to step over watchpoint" plans execute
before we call a public stop.  Otherwise, e.g. if you have N watchpoints and
a Signal, the signal stop info will get us to stop with the watchpoints in a
half-done state.

Differential Revision: https://reviews.llvm.org/D130674

This reverts commit 5778ada8e54edb2bc2869505b88a959d1915c02f.

The watchpoint tests all stall on aarch64-ubuntu bots.  Reverting till I can
get my hands on an system to test this out.

Since we want to present the "new & old" values for watchpoint hits, on architectures,
including the ARM family, that stop before the triggering instruction is run, we need
to single step over the instruction before stopping for realz.  This was incorrectly
done directly in the StopInfoWatchpoint::ShouldStop.  That causes problems if more than
one thread stops "for a reason" at the same time as the watchpoint, since the other actions
didn't expect the process to make progress in this part of the execution control machinery.

The correct way to do this is to schedule the step over using ThreadPlans, and then to restore
the stop info after that plan stops, so that the rest of the stop info actions can happen when
all the other threads have handled their immediate actions as well.

Differential Revision: https://reviews.llvm.org/D129814

Eliminate boilerplate of having each test manually assign to `mydir` by calling
`compute_mydir` in lldbtest.py.

Differential Revision: https://reviews.llvm.org/D128077

This test depends on multiple threads with one of them
hitting a watchpoint at the same time as a breakpoint, and
can fail because of the way arm64 watchpoints are handled.
I added skips to most of these via

```
commit bef4da4a6aef8196f007f44e3e9c8e3419ffb623
Author: Jason Molenda <jason@molenda.com>
Date:   Wed May 25 16:05:16 2022 -0700

    Skip testing of watchpoint hit-count/ignore-count on multithreaded
```

but missed that this test is susceptable to the same issue.

It was being used only in some very old tests (which pass even without
it) and its implementation is highly questionable.

These days we have different mechanisms for requesting a build with a
particular kind of c++ library (USE_LIB(STD)CPP in the makefile).

Replace the inline x86 watchpoint handling code with the reusable
NativeRegisterContextWatchpoint_x86.  Implement watchpoint support
in NativeThreadFreeBSD and SIGTRAP handling for watchpoints.

Un-skip all concurrent_events tests as they pass with the new plugin.

Differential Revision: https://reviews.llvm.org/D90102

Summary: Moves lldbsuite tests to lldb/test/API.

This is a largely mechanical change, moved with the following steps:

```
rm lldb/test/API/testcases
mkdir -p lldb/test/API/{test_runner/test,tools/lldb-{server,vscode}}
mv lldb/packages/Python/lldbsuite/test/test_runner/test lldb/test/API/test_runner
for d in $(find lldb/packages/Python/lldbsuite/test/* -maxdepth 0 -type d | egrep -v "make|plugins|test_runner|tools"); do mv $d lldb/test/API; done
for d in $(find lldb/packages/Python/lldbsuite/test/tools/lldb-vscode -maxdepth 1 -mindepth 1 | grep -v ".py"); do mv $d lldb/test/API/tools/lldb-vscode; done
for d in $(find lldb/packages/Python/lldbsuite/test/tools/lldb-server -maxdepth 1 -mindepth 1 | egrep -v "gdbremote_testcase.py|lldbgdbserverutils.py|socket_packet_pump.py"); do mv $d lldb/test/API/tools/lldb-server; done
```

lldb/packages/Python/lldbsuite/__init__.py and lldb/test/API/lit.cfg.py were also updated with the new directory structure.

Reviewers: labath, JDevlieghere

Tags: #lldb

Differential Revision: https://reviews.llvm.org/D71151