Merge branch 'feature/martin/cil/clean-cil' into 'master'

src/kernel_services/ast_printing/cil_printer.ml

src/kernel_services/ast_queries/cil.ml

src/kernel_services/ast_queries/cil.mli

src/kernel_services/ast_queries/logic_typing.ml

src/kernel_services/visitors/cabsvisit.ml

src/kernel_services/visitors/visitor.ml

src/libraries/stdlib/extlib.ml

src/libraries/stdlib/extlib.mli

tests/spec/Extend.ml