[ntuple] Enable subfield access in `REntry` #13065

Job	Run time
Windows 10 x64 Release	14s
Windows 10 x86 Release	57m 1s
mac13 ARM64 LLVM_ENABLE_ASSERTIONS=On, builtin_zlib=ON	27m 39s
mac14 X64 LLVM_ENABLE_ASSERTIONS=On, CMAKE_CXX_STANDARD=20	53m 13s
mac15 ARM64 LLVM_ENABLE_ASSERTIONS=On, CMAKE_CXX_STANDARD=20	21m 30s
mac-beta ARM64 LLVM_ENABLE_ASSERTIONS=On, CMAKE_CXX_STANDARD=20	26m 54s
Upload Event Payload	4s
fedora40 LLVM_ENABLE_ASSERTIONS=On, CMAKE_CXX_STANDARD=20	33m 0s
alma8 LLVM_ENABLE_ASSERTIONS=On	24m 38s
alma9 LLVM_ENABLE_ASSERTIONS=On, CMAKE_BUILD_TYPE=Debug	1h 24m 31s
ubuntu20 LLVM_ENABLE_ASSERTIONS=On	40m 9s
ubuntu22 imt=Off, LLVM_ENABLE_ASSERTIONS=On, CMAKE_BUILD_TYPE=Debug	1h 27m 8s
ubuntu2404 LLVM_ENABLE_ASSERTIONS=On, CMAKE_BUILD_TYPE=Debug	1h 39m 53s
debian125 LLVM_ENABLE_ASSERTIONS=On, CMAKE_CXX_STANDARD=20	39m 33s
alma9 modules_off runtime_cxxmodules=Off	31m 48s
alma9 march_native CMAKE_BUILD_TYPE=RelWithDebInfo, CMAKE_CXX_FLAGS=-march=native, CMAKE_C_FLAGS=-march=native, fortran=OFF	23m 25s
alma9 arm64 CMAKE_BUILD_TYPE=RelWithDebInfo, ccache=ON	34m 4s
alma9-clang clang LLVM_ENABLE_ASSERTIONS=On, CMAKE_C_COMPILER=clang, CMAKE_CXX_COMPILER=clang++	33m 31s
ubuntu2404-cuda gpu	27m 42s
	12h 25m 57s

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