RD llvm: suppress some useless warnings
RD llvm: suppress some useless warnings

do not warn on a funcptr call of only declared function
- make it silently unknown

Signed-off-by: Marek Chalupa <a05df156a69ad59faa9af9b666ef78009594c145@gmail.com>

mchalupa/dg,mchalupa/dg,mchalupa/dg,mchalupa/dg