tests/valgrind: forbid inlining of pl_*()
tests/valgrind: forbid inlining of pl_*()

We want the pl_*() names to be visible in the valgrind output, otherwise we
can't properly generalize the suppressions.

Unfortunately there doesn't seem to be a non-compiler-specific way to mark
functions as "not inline".  Fortunately, using a volatile function pointer
forces the compiler to not inline it.

Tarsnap/tarsnap-gui,shinnok/tarsnap-gui,shinnok/tarsnap-gui,Tarsnap/tarsnap-gui,shinnok/tarsnap-gui,Tarsnap/tarsnap-gui,shinnok/tarsnap-gui,Tarsnap/tarsnap-gui,shinnok/tarsnap-gui,Tarsnap/tarsnap-gui