GPUTracking: compile the real kernels into the Metal library

GPUReconstructionMETAL.metal had the device headers and the kernel list behind
#if 0, with a comment saying they do not compile as MSL yet. They do now, so the
entry point includes them and the library it produces contains the 96 kernels
rather than nothing.

Author: ktf

GPU/GPUTracking/Base/metal/GPUReconstructionMETAL.metal

@@ -47,16 +47,8 @@ using namespace metal;
 #include "GPUCommonTypeTraits.h"
 #include "GPUCommonArray.h"
 
-// The remaining headers do not compile as MSL yet, but nothing structural is in
-// the way: with the pragma above and the untyped constant buffer below, the
-// kernel list expands to all 104 entry points, with no derived-class and no
-// kernel-argument-type errors left. What fails is the bodies, and it is bulk
-// work rather than a missing language feature -- MSL has no double, and every
-// namespace-scope constexpr needs GPUglobalconstexpr().
-#if 0
 #include "GPUConstantMem.h"
 #include "GPUReconstructionIncludesDeviceAll.h"
-#endif
 
 // --- Kernel list expansion ---------------------------------------------------
 #define GPUCA_KRNL(...) GPUCA_KRNLGPU(__VA_ARGS__)
@@ -80,10 +72,7 @@ using namespace metal;
   , uint _metalTPerTg [[threads_per_threadgroup]] \
   , uint _metalTgPerG [[threadgroups_per_grid]]
 
-// Include the actual kernels, once the headers above compile as MSL.
-#if 0
 #include "GPUReconstructionKernelList.h"
-#endif
 
 // clang-format on
 #pragma clang diagnostic pop