Break up _pyrepl tests #119306
Description
I'd like to work on increasing the test coverage of the new _pyrepl module:
% ./python.exe ../coveragepy report --show-missing
Name Stmts Miss Branch BrPart Cover Missing
------------------------------------------------------------------------------
Lib/_pyrepl/__init__.py 0 0 0 0 100%
Lib/_pyrepl/__main__.py 35 35 16 0 0% 1-44
Lib/_pyrepl/_minimal_curses.py 38 38 12 0 0% 12-68
Lib/_pyrepl/commands.py 294 148 80 3 46% 56, 61-75, 96, 100, 110-126, 131-133, 138, 143-144, 149-157, 162-163, 168-170, 175-177, 182-184, 189-193, 198-211, 216-219, 224-236, 250-252, 286->exit, 309, 326, 331, 336, 341, 346-348, 353-355, 366-367, 372-385, 390-398, 403-418, 423, 428-431, 436-438, 443-444, 449-455
Lib/_pyrepl/completing_reader.py 151 19 52 10 85% 47-48, 66, 79-80, 88->100, 102->116, 174->177, 182-183, 190->192, 197-198, 214, 223, 278-284, 287
Lib/_pyrepl/console.py 33 0 22 0 100%
Lib/_pyrepl/curses.py 11 5 0 0 55% 24-28
Lib/_pyrepl/fancy_termios.py 25 7 0 0 72% 62-64, 67, 70, 73-74
Lib/_pyrepl/historical_reader.py 215 83 50 7 58% 58-62, 67-71, 76-81, 86, 91, 96, 101-124, 129-134, 149-154, 164->exit, 170-175, 180-182, 187-189, 272, 276-282, 289-292, 296-298, 315, 323-324, 327-329, 341->exit
Lib/_pyrepl/input.py 59 8 26 5 85% 52, 56, 60, 76, 83, 88, 94, 103
Lib/_pyrepl/keymap.py 77 9 46 9 85% 126, 131, 138, 143, 159, 165, 172, 181, 210
Lib/_pyrepl/pager.py 118 118 54 0 0% 1-173
Lib/_pyrepl/reader.py 358 65 130 20 78% 265-267, 271-273, 325-333, 345-354, 362-370, 377->379, 391, 411, 417, 430->432, 459, 477->489, 504->exit, 506, 522-524, 528, 538-546, 553-555, 558-559, 579, 591->594, 611, 622, 627, 633, 639-640, 649, 659-660
Lib/_pyrepl/readline.py 306 129 90 10 54% 122-127, 130->148, 133-134, 139-140, 151-157, 174-181, 186, 192-193, 195, 244->253, 247-252, 257, 273->275, 275->exit, 279-282, 285-291, 298-308, 311, 314, 317, 320, 323, 326-327, 330, 333, 336, 343-360, 363-368, 371, 374-378, 381-385, 389-393, 397, 400, 403-404, 407-413, 416, 419, 422, 463-465, 484-502
Lib/_pyrepl/simple_interact.py 89 68 16 0 22% 41-45, 74-75, 78, 84-158
Lib/_pyrepl/trace.py 13 5 6 2 53% 12, 18-21
Lib/_pyrepl/types.py 7 0 0 0 100%
Lib/_pyrepl/unix_console.py 428 161 140 21 61% 47, 112-126, 152, 157, 173, 215, 235, 288-292, 346-347, 355-362, 368-369, 381-397, 403, 412-415, 426-448, 454, 471-476, 482-483, 494-529, 535-539, 545, 551->560, 555-558, 562-565, 569-572, 575, 579, 613-614, 623-626, 636-645, 651, 659, 668->exit, 672-676, 686-687, 690-694, 712-713, 726-735, 752-762
Lib/_pyrepl/unix_eventqueue.py 69 6 20 4 89% 69, 93, 126, 143, 148-149
Lib/_pyrepl/utils.py 11 0 6 0 100%
------------------------------------------------------------------------------
TOTAL 2337 904 766 91 59%
However, with all the tests in the single file, it was seeming like it'd start to get unwieldy. As a first step, I'd like to break this test_pyrepl.py file apart.