pp_dlload as op (core)

Implement DynaLoader in C
One should not call perl to load a shared library.    

Implement a sane XSLoader API using that.
http://blogs.perl.org/users/rurban/2011/10/the-two-worst-perl-apis.html

-fcarp-as-warn (core)

Replace the 4 Carp calls with ops, which do die/warn and display
the backtrace as op.  Carp autoloads XS Carp::Heavy, and one
usecase is Carp in Dynaloader failing code.  It also has too much
dependencies

-fno-warnings (B::C, B::CC)

Production perl wants to choose no run-time warnings overhead.
fix current B::CC -fno-warnings -Uwarnings

nop warnings calls. some modules use warnif and fail with the
current -fno-warnings.  E.g. Find::File

compile-time utf8 folding tables

do not defer swash_init to run-time. mark the ops (lc,uc,fc,match)
as utf8 or ascii or undecided.  implement the folding tables as
shared objects, created at build-time (as Encode does)

implement exists symbol as op (lexical or global)

symbols should not be created when asking if a symbol exists.

implement last out of grep/map

tail recursion

implement the taint flag bit for HEKs

implement the run-time part for oplines

search for the upper cop in case of warnings/errors for the filename