tree f1c1cf2776e0266b829ee66ca6d124a31ea84f52
parent 084b3e3b835bb13c42c0658f033826ffa8e0f373
author Sameer Agarwal <sameeragarwal@google.com> 1773416857 -0700
committer Sameer Agarwal <sameeragarwal@google.com> 1773703146 -0700

Make test_util GTest-optional to fix benchmark builds with BUILD_TESTING=OFF

When Ceres is configured with BUILD_TESTING=OFF and BUILD_BENCHMARKS=ON,
benchmarks failed to compile and link due to an unconditional dependency on the
test_util library, which requires Googletest (GTest). This commit addresses the issue
by introducing the CERES_HAS_GTEST macro and making the test utility library
GTest-optional.

Fixes: https://github.com/ceres-solver/ceres-solver/issues/1081

Change-Id: I615c37eb6f21d36a4b87b2d24632016944eda3bd