Merge faster Riemann R function #69

Job	Run time
linux_clang (ubuntu-latest, Debug)	3m 40s
linux_gcc_sanitizers	2m 20s
linux_gcc (ubuntu-latest, Debug)	4m 40s
linux_clang (ubuntu-latest, Release)	1m 33s
linux_gcc (ubuntu-latest, Release)	2m 18s
macos_clang (macos-latest, Debug)	3m 1s
windows_mingw64 (windows-latest, Debug)	5m 11s
windows_msvc2022	2m 22s
macos_clang (macos-latest, Release)	1m 30s
windows_mingw64 (windows-latest, Release)	2m 46s
linux_gcc_valgrind	1m 16s
	30m 37s

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