* Fixes

detect &utf8::is_utf8 (Carp), re::* and more internals
fix dl_init() e.g. t/testm.sh File::Temp fails to init IO, threads also
'n' magic (shared_scalar) e.g. t/testm.sh Test::Tester

CC backend: goto (needs test), 
sort with non-default comparison. 
last for non-loop blocks (needs simplier test, test 29).
cc_queue error with the non-seperate sort optree, test 18

check failing modules:
  5.8: Attribute::Handlers B::Hooks::EndOfScope YAML MooseX::Types
  5.10: 35/77 Digest::SHA1, Getopt::Long, Encode, File::Path, IO, ...
improve XSUB handling (both static and dynamic, needs tests)
sv_magic can do SvREFCNT_inc(obj) which messes up precalculated refcounts
allocation of XPV[INAHC]V structures needs fixing: Perl tries to free
  them, whereas the compiler expects them to be linked to a xpv[inahc]v_root
list the same as X[IPR]V structures.
ref counts
perl_parse replacement
signed/unsigned problems with NV (and IV?) initialisation and elsewhere?
CvOUTSIDE for ordinary subs
DATA filehandle for C-compiled program (almost done)
pv_copy_on_grow no &PL_SV_undef in static inits

* Features

type checking: Devel::TypeCheck
compile time v. runtime initialisation:
  execute run-time BEGIN blocks for side-effects such as print or chdir, 
  use and require not.
save PMOPs in compiled form
selection of what to dump
options for cutting out line info (COP elimination) etc. (-fcop)
shared constants (share_hek, constpv)
check module dependencies, vs. link libs static, not via DynaLoader
new Asm, JIT or PIR backend, PLJC ByteLoader magic
check Bytecode op coverage in the tests, should cover all ops 0-142
ByteLoader compatibility: version, platform. eventually Bytecode version 
  portability (test with 5.6 on cygwin, partially done)
check CC op coverage, add tests

* Optimizations

collect static strings beforehand, such as GvNAMEs, COP FILENAME (for pre 5.10)
  and GV method names package::name. (partially done)
proper static init of PMOP SV's (only works dynamic >= 5.10)
proper static init of PVBM/FBM (almost done, just 5.8.9 not)
compile-time initialisation of AvARRAYs (improved with -fav-init, but slower)
collapse LISTOPs to UNOPs or BASEOPs
compile-time qw(), constant subs
variable types: global analysis of variables, type hints etc.
  understand type attrs
    my $i : Cint;
  Devel::TypeCheck instead of magic variable _ir, ... suffices
  e.g. mark IVonly SV's and magic/flags change functions and 
  optimize all op subtrees for the compiled backends to use direct ints.
  understand MooseX::Method::Signatures and MooseX::Lexical::Types declarations
demand-loaded bytecode (leader of each basic block replaced by an op
  which loads in bytecode for its block)
fast sub calls for CC backend
tailcall optimization (entersub -> leavesub => goto)
inline more small pp ops: enter, reset, stringify, ... (CC -finline-ops)