ARROW-6852: [C++] Fix build issue on memory-benchmark
ARROW-6852: [C++] Fix build issue on memory-benchmark

After the new commit: ARROW-6381 was merged in master,
build would fail on Arm64 when DARROW_BUILD_BENCHMARKS is enabled.

Closes #5624 from guyuqi/build-failed-membench and squashes the following commits:

ed94e1f9f <Yuqi Gu> ARROW-6852:  Fix build issue on memory-benchmark

Authored-by: Yuqi Gu <345a4e3af047c06b177f7fe1915a45f6033d9349@arm.com>
Signed-off-by: Antoine Pitrou <8ffbbac03241e3002f35c2a1f358cd318666d6e4@free.fr>

apache/arrow,apache/arrow,renesugar/arrow,cpcloud/arrow,kou/arrow,wesm/arrow,cpcloud/arrow,kou/arrow,kou/arrow,apache/arrow,xhochy/arrow,laurentgo/arrow,laurentgo/arrow,renesugar/arrow,icexelloss/arrow,cpcloud/arrow,icexelloss/arrow,apache/arrow,wesm/arrow,renesugar/arrow,laurentgo/arrow,icexelloss/arrow,icexelloss/arrow,xhochy/arrow,xhochy/arrow,apache/arrow,laurentgo/arrow,kou/arrow,renesugar/arrow,wesm/arrow,renesugar/arrow,xhochy/arrow,wesm/arrow,apache/arrow,laurentgo/arrow,wesm/arrow,apache/arrow,icexelloss/arrow,kou/arrow,cpcloud/arrow,xhochy/arrow,apache/arrow,kou/arrow,wesm/arrow,xhochy/arrow,cpcloud/arrow,xhochy/arrow,cpcloud/arrow,icexelloss/arrow,renesugar/arrow,cpcloud/arrow,cpcloud/arrow,xhochy/arrow,apache/arrow,kou/arrow,laurentgo/arrow,laurentgo/arrow,xhochy/arrow,kou/arrow,xhochy/arrow,xhochy/arrow,xhochy/arrow,icexelloss/arrow,apache/arrow,icexelloss/arrow,icexelloss/arrow,kou/arrow,xhochy/arrow,renesugar/arrow,cpcloud/arrow,laurentgo/arrow,cpcloud/arrow,renesugar/arrow,icexelloss/arrow,kou/arrow,laurentgo/arrow,wesm/arrow,cpcloud/arrow,wesm/arrow,renesugar/arrow,icexelloss/arrow,cpcloud/arrow,wesm/arrow,wesm/arrow,kou/arrow,renesugar/arrow,cpcloud/arrow,renesugar/arrow,wesm/arrow,wesm/arrow,wesm/arrow,laurentgo/arrow,xhochy/arrow,kou/arrow,laurentgo/arrow,apache/arrow,kou/arrow,apache/arrow,renesugar/arrow,renesugar/arrow,xhochy/arrow,apache/arrow,cpcloud/arrow,wesm/arrow,laurentgo/arrow,laurentgo/arrow,icexelloss/arrow,icexelloss/arrow,renesugar/arrow,renesugar/arrow,apache/arrow,icexelloss/arrow,laurentgo/arrow,laurentgo/arrow,kou/arrow