The Python script interpreter imports `pydoc` during initialization, but this can be
slow in some cases, and doesn't seem to be necessary any more.
This can be slow because pydoc may execute shell commands (for example `xcrun` on
macOS). The shell commands may have variable performance, depending on their caches and
search space.
The 2012 bug report for the original commit (f71a8399997bfdc1ddeeb30c6a8897554a11c382)
says the following:
> "script help" in lldb pipes the help documentation through less(1) but there's some
> problem with the key handling and often the keys you'd use to move in less (space to
> move down a page, 'q' to quit) are not received by less (they're going to lldb
> instead)
This was resolved at the time by overriding `pydoc`'s pager to be the `plainpager`
function.
I have manually tested `script help(lldb.SBDebugger)` and found no issues with the
pager, including using "space" for paging, "/" for searching, and "q" for quitting.
The presumption is that lldb and/or Python have improved I/O handling that eliminates
the original problem.
The original bug report gave an ~/.lldbinit workaround:
```
script import pydoc; pydoc.pager = pydoc.plainpager
```
Note that calling Python's `help()` will import `pydoc`, but this will only happen for
users who use `help()` from the `script` command.
Differential Revision: https://reviews.llvm.org/D144138