non-C99 inline in math-68881.h

[Thorsten Glaser]

math-68881.h as distributed with gcc 4.6.2 and gcc SVN trunk
uses “__inline extern” instead of C99 “static inline”.

bye,
//mirabilos
-- 
  “Having a smoking section in a restaurant is like having
          a peeing section in a swimming pool.”
                                                -- Edward Burr