Merge pull request #25686 from Kumataro:fix25674

Suppress build warnings for GCC14 #25686

Close #25674

### Pull Request Readiness Checklist

See details at https://github.com/opencv/opencv/wiki/How_to_contribute#making-a-good-pull-request

- [x] I agree to contribute to the project under Apache 2 License.
- [x] To the best of my knowledge, the proposed patch is not based on a code under GPL or another license that is incompatible with OpenCV
- [x] The PR is proposed to the proper branch
- [x] There is a reference to the original bug report and related work
- [ ] There is accuracy test, performance test and test data in opencv_extra repository, if applicable
      Patch to opencv_extra has the same branch name.
- [ ] The feature is well documented and sample code can be built with the project CMake

modules/ts/include/opencv2/ts/ts_gtest.h

@@ -21317,6 +21317,13 @@ AssertionResult CmpHelperEQFailure(const char* lhs_expression,
                    false);
 }
 
+// See https://github.com/opencv/opencv/issues/25674
+// Disable optimization for workaround to mis-branch for GCC14.
+#if defined(__GNUC__) && (__GNUC__ == 14)
+#pragma GCC push_options
+#pragma GCC optimize ("O0")
+#endif
+
 // The helper function for {ASSERT|EXPECT}_EQ.
 template <typename T1, typename T2>
 AssertionResult CmpHelperEQ(const char* lhs_expression,
@@ -21330,6 +21337,10 @@ AssertionResult CmpHelperEQ(const char* lhs_expression,
   return CmpHelperEQFailure(lhs_expression, rhs_expression, lhs, rhs);
 }
 
+#if defined(__GNUC__) && (__GNUC__ == 14)
+#pragma GCC pop_options
+#endif
+
 // With this overloaded version, we allow anonymous enums to be used
 // in {ASSERT|EXPECT}_EQ when compiled with gcc 4, as anonymous enums
 // can be implicitly cast to BiggestInt.