Merge faster Riemann R function #89

Job	Run time
linux_clang (ubuntu-latest, Debug)	3m 57s
macos_clang (macos-latest, Debug)	2m 56s
macos_clang (macos-latest, Release)	3m 49s
linux_clang (ubuntu-latest, Release)	1m 10s
linux_gcc_sanitizers	2m 22s
linux_gcc_valgrind	1m 8s
linux_gcc (ubuntu-latest, Debug)	4m 57s
windows_mingw64 (windows-latest, Debug)	5m 12s
linux_gcc (ubuntu-latest, Release)	2m 10s
windows_mingw64 (windows-latest, Release)	2m 44s
windows_msvc2022	2m 30s
	32m 55s

Provide feedback