Hi, This implements the GCC interface for IEEE Std 754 NaN interlinking, following the recommendations set out in the "MIPS ABI Extension for IEEE Std 754 Non-Compliant Interlinking" document available here: <https://dmz-portal.mips.com/wiki/MIPS_ABI_-_NaN_Interlinking>.
Two patches comprise the change, of which one is a preparatory clean-up and the other one implements the feature added. These changes have passed manual testing by compiling and linking objects with different options relevant here, i.e. the `-mieee=' and `-mrelaxed-nan=' options added here and the `-mnan=' option already supported. No full regression testing has been run. At this time this is an RFC only and therefore patches are posted despite stage 3. These patches are not meant to be merged before the document referred above has been finalised and corresponding binutils patches this feature relies on committed. Maciej
