COMPAT: 32-bit indexing compat
xref #20939

# [Codecov](https://codecov.io/gh/pandas-dev/pandas/pull/20977?src=pr&el=h1) Report
> Merging [#20977](https://codecov.io/gh/pandas-dev/pandas/pull/20977?src=pr&el=desc) into [master](https://codecov.io/gh/pandas-dev/pandas/commit/2299693d079033a0dd502ed5f59a4ad6e7a24b20?src=pr&el=desc) will **decrease** coverage by `<.01%`.
> The diff coverage is `50%`.

[![Impacted file tree graph](https://codecov.io/gh/pandas-dev/pandas/pull/20977/graphs/tree.svg?src=pr&token=eZ4WkYLtcO&width=650&height=150)](https://codecov.io/gh/pandas-dev/pandas/pull/20977?src=pr&el=tree)

```diff
@@            Coverage Diff             @@
##           master   #20977      +/-   ##
==========================================
- Coverage   91.82%   91.82%   -0.01%     
==========================================
  Files         153      153              
  Lines       49490    49490              
==========================================
- Hits        45445    45443       -2     
- Misses       4045     4047       +2
```

| Flag | Coverage Δ | |
|---|---|---|
| #multiple | `90.22% <50%> (-0.01%)` | :arrow_down: |
| #single | `41.85% <0%> (ø)` | :arrow_up: |

| [Impacted Files](https://codecov.io/gh/pandas-dev/pandas/pull/20977?src=pr&el=tree) | Coverage Δ | |
|---|---|---|
| [pandas/core/indexing.py](https://codecov.io/gh/pandas-dev/pandas/pull/20977/diff?src=pr&el=tree#diff-cGFuZGFzL2NvcmUvaW5kZXhpbmcucHk=) | `93.55% <50%> (ø)` | :arrow_up: |
| [pandas/util/testing.py](https://codecov.io/gh/pandas-dev/pandas/pull/20977/diff?src=pr&el=tree#diff-cGFuZGFzL3V0aWwvdGVzdGluZy5weQ==) | `84.38% <0%> (-0.21%)` | :arrow_down: |

------

[Continue to review full report at Codecov](https://codecov.io/gh/pandas-dev/pandas/pull/20977?src=pr&el=continue).
> **Legend** - [Click here to learn more](https://docs.codecov.io/docs/codecov-delta)
> `Δ = absolute <relative> (impact)`, `ø = not affected`, `? = missing data`
> Powered by [Codecov](https://codecov.io/gh/pandas-dev/pandas/pull/20977?src=pr&el=footer). Last update [2299693...09c1381](https://codecov.io/gh/pandas-dev/pandas/pull/20977?src=pr&el=lastupdated). Read the [comment docs](https://docs.codecov.io/docs/pull-request-comments).
