libnixf: diagnose non-associative operators #3189

Job	Run time
nix-build-develop-clang (none, release, true)	2m 53s
nix-build-develop-clang (none, release, false)	2m 55s
nix-build-develop-clang (none, debug, true)	2m 48s
nix-build-develop-gcc (none, release, true)	3m 7s
nix-build-develop-clang (none, debug, false)	2m 51s
nix-build-develop-gcc (none, release, false)	2m 59s
nix-build-develop-gcc (none, debug, true)	3m 3s
nix-build-develop-gcc (none, debug, false)	2m 57s
nix-build-develop-gcc (address, release, true)	4m 41s
nix-build-develop-gcc (address, release, false)	4m 33s
nix-build-develop-gcc (address, debug, true)	4m 3s
nix-build-develop-gcc (address, debug, false)	4m 5s
nix-build-develop-gcc (undefined, release, true)	4m 3s
nix-build-develop-gcc (undefined, release, false)	4m 13s
nix-build-develop-gcc (undefined, debug, true)	3m 22s
nix-build-develop-gcc (undefined, debug, false)	3m 29s
	56m 2s

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