Re: [Libguestfs] [PATCH 1/2] tools: Link OCaml programs with -runtime-variant _pic if available.

OCaml has a small runtime which is statically linked into the virt tools (providing things like GC and primitives). Since OCaml 4.03 it has been possible to select variants of this runtime, one of which is compiled with -fPIC, using ‘ocamlopt -runtime-variant _pic’. This has performance implications on i686, but is relatively free on other architectures. Since it (in theory) adds to the security of the final binary this commit enables it whenever it is available. ---