MINOR: [C++] Add missing header for ORC adapter

[mikelui]

Rationale for this change

Very minor. This source file cannot be compiled on its own manually, due to missing stringstream headers. This fixes that. Otherwise we get implicit instantiation of undefined template errors.

Context is we build Apache Arrow in a separate build system, Buck. As such, we do not (and cannot) 100% mirror the CMake build. In the past we've also had to patch header issues like: 529e08c. Thus, this change is for posterity to avoid having to custom patches on every new release.

What changes are included in this PR?

Adds which is used here:
https://github.com/apache/arrow/blob/main/cpp/src/arrow/adapters/orc/util.cc#L1226

Are these changes tested?

N/A

Are there any user-facing changes?

No

[kou]

+1

[conbench-apache-arrow]

After merging your PR, Conbench analyzed the 3 benchmarking runs that have been run so far on merge-commit 857092c.

There were 132 benchmark results with an error:

• Commit Run on arm64-t4g-2xlarge-linux at 2024-11-28 03:50:32Z
  • tpch (R) with engine=arrow, format=parquet, language=R, memory_map=False, query_id=TPCH-07, scale_factor=1
  • tpch (R) with engine=arrow, format=native, language=R, memory_map=False, query_id=TPCH-09, scale_factor=1
• and 130 more (see the report linked below)

There were no benchmark performance regressions. 🎉

The full Conbench report has more details. It also includes information about 3 possible false positives for unstable benchmarks that are known to sometimes produce them.