/usr/include/bullet/Bullet3OpenCL/RigidBody/ is in libbullet-dev 2.87+dfsg-2.
This file is owned by root:root, with mode 0o755.
..
/usr/include/bullet/Bullet3OpenCL/RigidBody/b3GpuConstraint4.h
/usr/include/bullet/Bullet3OpenCL/RigidBody/b3GpuGenericConstraint.h
/usr/include/bullet/Bullet3OpenCL/RigidBody/b3GpuJacobiContactSolver.h
/usr/include/bullet/Bullet3OpenCL/RigidBody/b3GpuNarrowPhase.h
/usr/include/bullet/Bullet3OpenCL/RigidBody/b3GpuNarrowPhaseInternalData.h
/usr/include/bullet/Bullet3OpenCL/RigidBody/b3GpuPgsConstraintSolver.h
/usr/include/bullet/Bullet3OpenCL/RigidBody/b3GpuPgsContactSolver.h
/usr/include/bullet/Bullet3OpenCL/RigidBody/b3GpuRigidBodyPipeline.h
/usr/include/bullet/Bullet3OpenCL/RigidBody/b3GpuRigidBodyPipelineInternalData.h
/usr/include/bullet/Bullet3OpenCL/RigidBody/b3GpuSolverBody.h
/usr/include/bullet/Bullet3OpenCL/RigidBody/b3GpuSolverConstraint.h
/usr/include/bullet/Bullet3OpenCL/RigidBody/b3Solver.h
/usr/include/bullet/Bullet3OpenCL/RigidBody/kernels/
/usr/include/bullet/Bullet3OpenCL/RigidBody/kernels/batchingKernels.h
/usr/include/bullet/Bullet3OpenCL/RigidBody/kernels/batchingKernelsNew.h
/usr/include/bullet/Bullet3OpenCL/RigidBody/kernels/integrateKernel.h
/usr/include/bullet/Bullet3OpenCL/RigidBody/kernels/jointSolver.h
/usr/include/bullet/Bullet3OpenCL/RigidBody/kernels/solveContact.h
/usr/include/bullet/Bullet3OpenCL/RigidBody/kernels/solveFriction.h
/usr/include/bullet/Bullet3OpenCL/RigidBody/kernels/solverSetup.h
/usr/include/bullet/Bullet3OpenCL/RigidBody/kernels/solverSetup2.h
/usr/include/bullet/Bullet3OpenCL/RigidBody/kernels/solverUtils.h
/usr/include/bullet/Bullet3OpenCL/RigidBody/kernels/updateAabbsKernel.h