Add better support for armv7a cross compilation #2919

Job	Run time
cabal	41s
build-extra-hackages	38s
cabal-doExactConfig	41s
check-materialization-concurrency	19s
check-path-support	15s
closure-size	3s
docs	2m 28s
haskell-nix-roots-do-not-require-IFDs	1h 30m 12s
hix	1h 39m 35s
hix-cabal	3m 3s
hydra-ifdLevel-0-and-1	6m 1s
hydra-ifdLevel-2	19m 10s
hydra-ifdLevel-3	30m 16s
hydra-without-remote-builders-ghc9101	4m 34s
hydra-without-remote-builders-ghc966	2m 42s
maintainer-scripts	33s
multi-target	3m 6s
nix-build	16m 51s
nix-tools	17s
plan-extra-hackages	6s
runghc	9s
shellFor-hoogle	2m 54s
shellFor-multiple-package	50s
shellFor-not-depends	15s
shellFor-single-package	1m 48s
tests-benchmarks	7s
unit-tests	8s
update-docs	25s
	4h 48m 7s

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