-Ur option documentation

[Nick Clifton]

Hi Florian,

> Andreas said that DT_INIT should still work with -Ur, so maybe you don't
> need the SHT_INIT_ARRY clarification?

So:

     For programs that do not use constructors or destructors,
     or for ELF based systems this option is equivalent to -r:
     it generates relocatable output -- i.e., an output file
     that can in turn serve as input to ld.  For other binaries
     however the -Ur option is similar to -r but it also resolves
     references to constructors and destructors.

     It does not work to use -Ur on files that were themselves
     linked with -Ur; once the constructor table has been built,
     it cannot be added to.  Use -Ur only for the last partial
     link, and -r for the others.

Cheers
   Nick