Changes are many, important for pkgsrc:
- much higher speed (up to 30% faster for the overall build of libX11)
- less magic for detection of the tag
The pkgsrc integration of f2c has been changed to be more sane.
libtool itself now depends on the f2c frontend to use proper
auto-configuration and only fakes up the library. This part is
encapsulated in mk/compiler/f2c.mk.