"Unsupported argument with another option" build failure(s) — clang 3.4.2

PackageVersionSupposed error messageFull log Bug report
3dchess 0.8.1-18clang: error: unsupported option '-fpcc-struct-return' for target 'x86_64-pc-linux-gnu' Log
autodock-vina 1.1.2-3clang: error: unsupported option '--lto' Log
freecontact 1.0.21-3clang: error: unsupported option '--help=optimizers' Log
klibc 2.0.3-1clang: error: unsupported option '--print-libgcc' Log
libffi 3.1-2clang: error: unsupported argument '--gdwarf2' to option 'Wa,' Log
mlton 20100608-5.1clang: error: unsupported option '-gstabs+' Log
syslinux 3:6.03~pre14+dfsg-2clang: error: unsupported option '--print-libgcc' Log
validns 0.7-1clang: error: unsupported option '--no-strict-aliasing' Log

8 errors