Prevent config.h from being clobbered

corepkgs/fetchurl.nix

doc/dev/release-procedures.txt

doc/manual/builtins.xml

doc/manual/opt-common.xml

doc/manual/release-notes.xml

perl/lib/Nix/Store.xs

scripts/build-remote.pl.in

src/libexpr/eval.cc

src/libexpr/nixexpr.hh

src/libexpr/parser.y

src/libexpr/primops.cc

src/libmain/shared.cc

src/libstore/build.cc

src/libstore/gc.cc

src/libstore/globals.cc

src/libstore/globals.hh

src/libstore/local-store.cc

src/libstore/local-store.hh

src/libstore/optimise-store.cc

src/libstore/remote-store.cc