[SR-15913] Latest nightly snapshots have a broken lldb on focal

[Lukasa]

Previous ID	SR-15913
Radar	rdar://problem/89641524
Original Reporter	@Lukasa
Type	Bug

Environment

Swift version 5.7-dev (LLVM f255403, Swift 496da9d)
Ubuntu 20.04.4 LTS

Additional Detail from JIRA

Votes	0
Component/s	LLDB for Swift
Labels	Bug
Assignee	@JDevlieghere
Priority	Medium

md5: 8343654c29713b6432fbbc6688cc4772

Issue Description:

If you download and use the latest nightly snapshot from trunk for Ubuntu Focal (swift-DEVELOPMENT-SNAPSHOT-2022-02-22-a-ubuntu20.04) and try to use its lldb, you are greeted with:

Traceback (most recent call last):
  File "<string>", line 1, in <module>
ModuleNotFoundError: No module named 'lldb'

If you install lldb from the package archive (sudo apt-get install lldb) you instead get:

Traceback (most recent call last):
  File "<string>", line 1, in <module>
  File "/usr/lib/python3/dist-packages/lldb/__init__.py", line 11409, in <module>
    class SBTraceOptions(object):
  File "/usr/lib/python3/dist-packages/lldb/__init__.py", line 11468, in SBTraceOptions
    __swig_destroy__ = _lldb.delete_SBTraceOptions
AttributeError: module '_lldb' has no attribute 'delete_SBTraceOptions'

Both of these leave a semi-functional lldb that is incapable of symbolicating Swift backtraces.

[Lukasa]

@swift-ci create