Added function dwarf_iterate_fde_all_regs3() which
lets callers get all rows of the .debug_frame
and .eh_frame sections via callbacks the function
makes to a function you write. Simple to use
and, for FDEs with many rows, sixty times faster.
Added function dwarf_set_harmless_errors_enabled() which
enables turning off tests for harmless errors and that
makes a performance improvement for some calls.
dwarf_set_frame_rule_table_size() now allows setting
register rules table size as low as 50 entries, though
the default remains DW_FRAME_LAST_REG_NUM (189).