Set PIC for C as well. #2670

Job	Run time
build-extra-hackages	2m 3s
check-materialization-concurrency	21s
cabal-doExactConfig	2m 43s
cabal	3m 1s
check-path-support	1m 25s
closure-size	4s
docs	23s
haskell-nix-roots-do-not-require-IFDs	1m 5s
hix	7m 11s
hix-cabal	3m 33s
hydra-ifdLevel-0-and-1	5m 2s
hydra-ifdLevel-2	12m 32s
hydra-ifdLevel-3	30m 10s
hydra-without-remote-builders-ghc8107	2m 16s
hydra-without-remote-builders-ghc9101	2m 2s
maintainer-scripts	8s
multi-target	1m 18s
nix-build	46m 25s
nix-tools	17s
plan-extra-hackages	6s
runghc	7s
shellFor-hoogle	13m 10s
shellFor-multiple-package	12m 55s
shellFor-not-depends	31s
shellFor-single-package	31s
tests-benchmarks	24s
unit-tests	15s
update-docs	7s
	2h 30m 5s

Provide feedback