GPU: three additional Metal adaptations

[ktf]

GPUCommonAlgorithm::sortOnDevice takes an auto parameter, which is C++20. It is already skipped for OpenCL, at C++17, and MSL 4.1 reports C++17 as well.

GPUTPCTrackParam::TransportToXAlpha declares its material constants static at function scope, which MSL rejects; constexpr without static is accepted, as in SMatrixGPU.

Guard SMatrixGPU C++20 code using __cplusplus version macro.

[ktf]

@davidrohr the static is again safe, IMHO. I think the idea of guarding features based on the standard and not the backend is better than if !define(__OPENCL__) && !defined(__METAL__).

[alibuild]

Error while checking build/O2/fullCI_slc9 for 06bc5e9 at 2026-09-25 09:53:

## sw/BUILD/o2codechecker-latest/log
100% tests passed, 0 tests failed out of 1


## sw/BUILD/O2-latest/log
Error: missing ; at end of rule at /sw/SOURCES/O2/slc9_x86-64-slc9_x86-64/0/Detectors/TPC/base/src/TPCBaseLinkDef.h:75:56
Error: missing ; at end of rule at /sw/SOURCES/O2/slc9_x86-64-slc9_x86-64/0/Detectors/TPC/base/src/TPCBaseLinkDef.h:83:135
Error: missing ; at end of rule at /sw/SOURCES/O2/slc9_x86-64-slc9_x86-64/0/Detectors/TPC/base/src/TPCBaseLinkDef.h:84:135
Error: missing ; at end of rule at /sw/SOURCES/O2/slc9_x86-64-slc9_x86-64/0/Detectors/Upgrades/ALICE3/ECal/base/src/ECalBaseLinkDef.h:19:48
Error: missing ; at end of rule at /sw/SOURCES/O2/slc9_x86-64-slc9_x86-64/0/Detectors/Upgrades/ALICE3/RICH/base/src/RICHBaseLinkDef.h:18:48
Error: missing ; at end of rule at /sw/SOURCES/O2/slc9_x86-64-slc9_x86-64/0/Detectors/Upgrades/ALICE3/MID/base/src/MI3BaseLinkDef.h:18:47


## sw/BUILD/O2-full-system-test-latest/log
command o2-sim --field=ccdb --vertexMode kCollContext --seed 12345 -n 5 --configKeyValues "Diamond.width[2]=6.;GenTPCLoopers.colsys=PbPb;" -g pythia8hi -e TGeant4 -j 24 --run 310000 -o o2sim --fromCollContext collisioncontext.root:o2sim had nonzero exit code 1
[ERROR] SHUTTING DOWN DUE TO SIGNALED EXIT IN COMPONENT 646
[09:52:23][ERROR] CCDBDownloader CURL transfer error - Timeout was reached
[09:52:23][ERROR] CcdbDownloader finished transfer http://alice-ccdb.cern.ch/Users/m/mgiacalo/WGAN_ExtGenPair for 1790322738058 (agent_id: o2-sim-primary-/o2-sim-primary-server-device-runner@624 target/Linux_x86_64 init/1790322737335 id/mesosci@pcapiserv07 session/sgFIDs8J) with http code: 0
[09:52:23][ERROR] File Users/m/mgiacalo/WGAN_ExtGenPair could not be retrieved. No more hosts to try.
[09:52:23][ERROR] Unable to find object Users/m/mgiacalo/WGAN_ExtGenPair/1790322738058, Aborting
[09:52:23][FATAL] Error: issues in retrieving Users/m/mgiacalo/WGAN_ExtGenPair from CCDB!
[09:53:23][ERROR] No configuration received within 60000ms
[09:53:24][ERROR] Could not initialize simulation


## sw/BUILD/o2checkcode-latest/log
--
========== List of errors found ==========
++ GRERR=0
++ grep -v clang-diagnostic-error error-log.txt
++ grep ' error:'
grep: error-log.txt: binary file matches
++ GRERR=1
++ [[ 1 == 0 ]]
++ mkdir -p /sw/INSTALLROOT/c6fab19cd31688ba86120575bfb5584ede65eb37/slc9_x86-64/o2checkcode/1.0-local2/etc/modulefiles
++ alibuild-generate-module
+ HAS_BIN=
+ HAS_LIB=
+ HAS_CMAKE=
+ HAS_ROOT=
+ '[' 0 '!=' 0 ']'
+ cat
+ printf 'if ![ is-loaded '\''BASE/1.0'\'' ] {\n module load BASE/1.0\n}'
+ echo 'BUILD_REQUIRES=CMake alibuild-recipe-tools defaults-release'
BUILD_REQUIRES=CMake alibuild-recipe-tools defaults-release
+ FULL_BUILD_REQUIRES='ninja double-conversion googlebenchmark CMake alibuild-recipe-tools MPFR bz2 safe_int Alice-GRID-Utils UUID date pytorch_cpuinfo Python-modules-list ninja-fortran FairCMakeModules defaults-release O2-customization json-c'
+ echo 'FULL_BUILD_REQUIRES=ninja double-conversion googlebenchmark CMake alibuild-recipe-tools MPFR bz2 safe_int Alice-GRID-Utils UUID date pytorch_cpuinfo Python-modules-list ninja-fortran FairCMakeModules defaults-release O2-customization json-c'
FULL_BUILD_REQUIRES=ninja double-conversion googlebenchmark CMake alibuild-recipe-tools MPFR bz2 safe_int Alice-GRID-Utils UUID date pytorch_cpuinfo Python-modules-list ninja-fortran FairCMakeModules defaults-release O2-customization json-c
++ env
[0 more errors; see full log]

Full log here.

[ktf]

Discussed and agreed offline.