GPU: Some protection so we get a compiler warning when headers are included in wrong order

Author: davidrohr

GPU/Common/GPUCommonRtypes.h

@@ -20,14 +20,14 @@
 #if defined(GPUCA_STANDALONE) || (defined(GPUCA_O2_LIB) && !defined(GPUCA_O2_INTERFACE)) || defined(GPUCA_GPUCODE) // clang-format off
   #if !defined(ROOT_Rtypes) && !defined(__CLING__)
     #define GPUCOMMONRTYPES_H_ACTIVE
+    struct MUST_NOT_USE_Rtypes_h {};
+    typedef MUST_NOT_USE_Rtypes_h TClass;
     #define ClassDef(name,id)
     #define ClassDefNV(name, id)
     #define ClassDefOverride(name, id)
     #define ClassImp(name)
     #define templateClassImp(name)
     #ifndef GPUCA_GPUCODE_DEVICE
-//      typedef uint64_t ULong64_t;
-//      typedef uint32_t UInt_t;
       #include <iostream>
     #endif
   #endif

GPU/Common/GPUROOTSMatrixFwd.h

@@ -52,7 +52,7 @@ template <class T, uint32_t D1, uint32_t D2>
 class MatRepStdGPU;
 } // namespace detail
 
-#if !defined(GPUCA_STANDALONE) && !defined(GPUCA_GPUCODE)
+#if !defined(GPUCA_STANDALONE) && !defined(GPUCA_GPUCODE) && !defined(GPUCOMMONRTYPES_H_ACTIVE)
 template <typename T, uint32_t N>
 using SVector = ROOT::Math::SVector<T, N>;
 template <class T, uint32_t D1, uint32_t D2, class R>