Revert "GPU: Workaround for Clang Frontend issue"

This reverts commit 89b35ba.

Author: davidrohr

GPU/GPUTracking/Base/cuda/GPUReconstructionCUDAGenRTC.cxx

@@ -38,11 +38,7 @@ int32_t GPUReconstructionCUDA::genRTC(std::string& filename, uint32_t& nCompile)
 {
   std::string rtcparam = std::string("#define GPUCA_RTC_CODE\n") +
                          std::string(GetProcessingSettings().rtc.optSpecialCode ? "#define GPUCA_RTC_SPECIAL_CODE(...) __VA_ARGS__\n" : "#define GPUCA_RTC_SPECIAL_CODE(...)\n") +
-#ifndef GPUCA_HIP_WORKAROUND_CONSTEXPR // TODO: Fixme, once we have C++ P2280R4 in Clang
                          std::string(GetProcessingSettings().rtc.optConstexpr ? "#define GPUCA_RTC_CONSTEXPR constexpr\n" : "#define GPUCA_RTC_CONSTEXPR\n") +
-#else
-                         std::string("#define GPUCA_RTC_CONSTEXPR\n") +
-#endif
                          GPUParamRTC::generateRTCCode(param(), GetProcessingSettings().rtc.optConstexpr);
   if (filename == "") {
     filename = "/tmp/o2cagpu_rtc_";

GPU/GPUTracking/Base/hip/CMakeLists.txt

@@ -270,8 +270,3 @@ add_dependencies(GPUTrackingHIPExternalProvider O2::GPUTracking) # must not depe
 if(NOT DEFINED GPUCA_HIP_HIPIFY_FROM_CUDA OR "${GPUCA_HIP_HIPIFY_FROM_CUDA}")
   add_dependencies(GPUTrackingHIPExternalProvider ${MODULE}_HIPIFIED)
 endif()
-
-set_source_files_properties("${GPUCA_HIP_SOURCE_DIR}/GPUReconstructionHIPGenRTC.cxx"
-TARGET_DIRECTORY O2::GPUTrackingHIP
-PROPERTIES
-COMPILE_DEFINITIONS "GPUCA_HIP_WORKAROUND_CONSTEXPR")