Change calling convention of dwarf_getmacros to allow opcode 0xff

We now require callers to pass DWARF_GETMACROS_START to start the
iteration.  0 is still accepted, but signals to libdw that the
iteration request comes from an old-style caller, and that opcode 0xff
should be rejected when iterating .debug_macro, to avoid confusion.

Signed-off-by: Petr Machata <pmachata@redhat.com>
9 files changed