[C++] Multiple test failures on PowerPC (big endian), on 15.0.2

### Describe the bug, including details regarding any error messages, version, and platform.

When running the test suite on Gentoo PowerPC (POWER9), I'm getting the following test failures:

```
The following tests FAILED:
18 - arrow-compute-internals-test (Failed)
25 - arrow-utility-test (Failed)
40 - parquet-internals-test (Failed)
41 - parquet-reader-test (Failed)
43 - parquet-arrow-test (Failed)
44 - parquet-arrow-internals-test (Failed)
45 - parquet-encryption-test (Failed)
46 - parquet-encryption-key-management-test (Failed)
Errors while running CTest
```

Build log: [build.txt](https://github.com/apache/arrow/files/14731364/build.txt)
Test log: [test.txt](https://github.com/apache/arrow/files/14731370/test.txt)

Some of them clearly look like endianness issues, others are unclear to me.

### Component(s)

C++