(parse_dynamic): Fix it so it actually works.
(create_state_record_for): Initialize return_link_reg to zero.
Don't print "no unwind info" unconditionally when UNW_DEBUG is
in effect.
(Logical change 1.56)
(desc_prologue): Fix handling of region_start so it doesn't get corrupted by
state-record pushing/popping.
(parse_dynamic): Allow the last region to contain a negative insn_count, indicating
that the region covers the last portion of a procedure.
(Logical change 1.54)
(create_state_record_for): Turn on UNW_PI_FLAG_IA64_RBS_SWITCH when a procedure
has saved all of ar.bsp, ar.bspstore, and ar.rnat.
(Logical change 1.40)