Failing on the macOS matrix bot for Clang-15 with the following error:
```
07:16:08  FAIL: LLDB (/Users/ec2-user/jenkins/workspace/llvm.org/lldb-cmake-matrix/clang_1501_build/bin/clang-arm64) :: test_jump_offset_dwarf (TestThreadJump.ThreadJumpTestCase)
07:16:08  UNSUPPORTED: LLDB (/Users/ec2-user/jenkins/workspace/llvm.org/lldb-cmake-matrix/clang_1501_build/bin/clang-arm64) :: test_jump_offset_dwo (TestThreadJump.ThreadJumpTestCase) (test case does not fall in any category of interest for this run)
07:16:08  Restore dir to: /Users/ec2-user/jenkins/workspace/llvm.org/lldb-cmake-matrix/lldb-build/tools/lldb/test
07:16:08  ======================================================================
07:16:08  FAIL: test_jump_offset_dsym (TestThreadJump.ThreadJumpTestCase)
07:16:08     Test Thread Jump by negative or positive offset
07:16:08  ----------------------------------------------------------------------
07:16:08  Traceback (most recent call last):
07:16:08    File "/Users/ec2-user/jenkins/workspace/llvm.org/lldb-cmake-matrix/llvm-project/lldb/packages/Python/lldbsuite/test/lldbtest.py", line 1804, in test_method
07:16:08      return attrvalue(self)
07:16:08    File "/Users/ec2-user/jenkins/workspace/llvm.org/lldb-cmake-matrix/llvm-project/lldb/test/API/functionalities/thread/jump/TestThreadJump.py", line 112, in test_jump_offset
07:16:08      self.expect(f"print {var_2}", substrs=[var_2_value])
07:16:08    File "/Users/ec2-user/jenkins/workspace/llvm.org/lldb-cmake-matrix/llvm-project/lldb/packages/Python/lldbsuite/test/lldbtest.py", line 2512, in expect
07:16:08      self.fail(log_msg)
07:16:08  AssertionError: Ran command:
07:16:08  "print var_2"
07:16:08
07:16:08  Got output:
07:16:08  (int) 20
07:16:08
07:16:08  Expecting sub string: "40" (was not found)
```

Fixes #45326 

When you thread jump by calling 
`j +2` or `thread jump --by +2` the offset is not recognised. This
commit fixes that.

---------

Signed-off-by: Ebuka Ezike <yerimyah1@gmail.com>

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

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

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

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).

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