The only change is a fix for the "register" iterator test to not rely on
particular register names.

I mistook where the artificial "pc" register is generated. It isn't
added to the register list or the register sets (except on arm where
that's the name of the actual register), so I can't use it in this test.
I instead just assert that the "register" generator produces the same
list as flattening the register sets from "registers".

This reverts commit 9f14914753599f3879e4c273191959e2f1b3632c.

Reverts llvm/llvm-project#88047. TestFrames.py is failing on x86_64
GreenDragon:
https://green.lab.llvm.org/job/llvm.org/view/LLDB/job/lldb-cmake/983/

The code returned lldb.SBValue() when you passed in an unrecognized
register name. But referring to "lldb" is apparently not legal within
the module.

I changed this to just return SBValue(), but then this construct:

(lldb) script
>>> for reg_set in lldb.target.process.thread[0].frames[0].register
...    print(reg)

Runs forever printing "No Value". The __getitem__(key) gets called with
a monotonically increasing by 1 series of integers. I don't know why
Python decided the class we defined should have a generator that returns
positive integers in order, but we can add a more useful one here by
returning an iterator over the flattened list of registers.

Note, the not very aptly named "SBFrame.registers" is an iterator over
register sets, not registers, so the two are not redundant.

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

Not needed now that we require python 3.

Reviewed By: kastiglione, JDevlieghere

Differential Revision: https://reviews.llvm.org/D131761

With lldb (& llvm) requiring Python 3.6+, use of the `six` module can be removed.

Differential Revision: https://reviews.llvm.org/D131304

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

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

Follow to D127355, converting more `assertEquals` to `assertState`.

Differential Revision: https://reviews.llvm.org/D127378

There is a .categories file in the python_api directory that makes all nested tests
belong to the category "pyapi". The decorator is unnecessary for these tests.

Follow up to D95813, this converts multiline assertTrue to assertEqual.

Differential Revision: https://reviews.llvm.org/D95899