Various small fixes.
examples: add sranges, for dumping the variables not included by aranges.

--HG--
rename : examples/coretest.cpp => examples/sranges.cpp
Disable CU interval map for now.
Split visible_grandchild_pos into overridable search function and cache logic.
lib::dieset: use core for faster next_visible_grandchild_with_name.
Merged.
examples: added core-query, mainly to test core resolve_visible changes.
Fixed to resolve_visible and friends.
Faster children_iterator getters for compile_unit_die.
Minor fixes.
adt.cpp: don't die if asked for the stack location of a static variable.
adt.cpp: disable verbose debugging printout for resolve_visible et al.
spec/dwarf3.py: add inheritance to structs.
spec_adt.hpp,adt.cpp: import type canonicalisation code from Cake.
rep.cpp: avoid infinite recursion in base type case.
Merged.
Fix infinite recursion in rep compatibility logic.
rep.cpp: fix bug testing subroutine_types for rep-compatibility.
Quieten certain error printouts in adt.cpp and rep.cpp.
canonicalise_type: don't resolve_all_visible, just rely on find_my_definition.
Various small fixes.
core.hpp: new, fast iteration interface. Work in progress.