Hello,

This patch modifies ppc64's convert_from_func_ptr_addr so that it only 
converts a descriptor to the code address when it's sure it's got a 
descriptor.  This way, of the function gets fed a random address, it 
doesn't map it onto something even more random - I encountered this when 
trying to debug "break main" with only a minimal symbol table.

This also makes the behavior consistent with the ia64.

ok?
Andrew