-- Without -stubdir, we just #include the basename
-- (eg. for a module A.B, we #include "B_stub.h"),
-- relying on the fact that we add an implicit -I flag
-- for the directory in which the source file resides
-- (see DriverPipeline.hs). With -stubdir, we
-- Without -stubdir, we just #include the basename
-- (eg. for a module A.B, we #include "B_stub.h"),
-- relying on the fact that we add an implicit -I flag
-- for the directory in which the source file resides
-- (see DriverPipeline.hs). With -stubdir, we