-fvia-C for libHSbase, etc.?

I'm building GHC on NetBSD-amd64, and among other things need to deal with the problem described in #2305 - native code misses the __RENAME (__asm) directive in NetBSD include files, and ends up linking to the wrong externals. The author of #2305 reports that -fvia-C avoids this problem, so I built the ghc 5/31 distribution I've been working on, with GhcLibHcOpts=-O -Rghc-timing -fgenerics -fvia-C (i.e., add -fvia-C compile option for library build.) Does that seem like a reasonable solution? It does seem to work, but I'm wondering if there are issues we can expect with performance etc.? thanks, -- Donn Cave