[tlbuild] PPC builds

[Bruno Haible]

Hi Johannes,

> I did have a Debian Jessie installation, so I had to try. The new clisp
> fails to build with some strange memory allocation error.

I'm interested in fixing this. Can you please give details:
  - Which version of "Debian Jessie" exactly, on which architecture?
  - Which gcc options relevant to architecture were used (such as -m32/-m64?)?
  - Can you copy&paste the complete output of that memory allocation error?

Bruno