Mk4tcl builds needs -fPIC for "ld"

On OpenBSD 4.0 Desktop / amd64 this error is given during a genkit build:

g++ -shared -o Mk4tcl.so mk4tcl.o mk4too.o column.o custom.o derived.o fileio.o field.o format.o handler.o persist.o remap.o std.o store.o string.o table.o univ.o view.o viewx.o -lpthread /usr/bin/ld: /usr/lib/gcc-lib/amd64-unknown-openbsd4.0/3.3.5/libgcc.a(unwind-dw2.o): relocation R_X86_64_32S can not be used when making a shared object; recompile with -fPIC

(Reported by Siju G on the starkit mailing list)