Bytecode 1.16: use our own walksymtable

also use Bytecode,-s > 5.18.
honor TEST_VERBOSE=2 for bytecode also (plctest)

use bwarn for Bytecode warnings.
most plctest cases seem to work now.
Bytecode: skip empty xcv_start (e.g. with 5.18 main_cv)

apparently with 5.18 main_cv->START can now be empty.

also add a flushing "\n" to the src files.
simplify -H/-s logic in t/bytecode.t
use proper -Iblib/arch -Iblib/lib, not -Mblib
C: revise sharedlibrary ptr to 0x40_0000

re-enable TODO for t/issue130.t BC test > 5.18thr
fix t/testc.sh 309 result
C 1.47_04: Better fix for mult. match once

checking OP_MATCH with ONCE flags in C.xs also, fixes #274.
Add runloop -DD debugging printout for found pmop => rx mappings.
Create a non-existing %B::C::Regexp hash to store the mappings, if non-exists.
t/CORE/mro/isarev.t: improve

avoid unsupported glob assignments.
see also #353 for the failing tests there (low prio)
collapse dbg print (-Dp,-v) of Deleting from %INC
Bytecode: fix 5.18 and 5.20, empty main_cv->START optree since 5.18
Bytecode: unTODO all 5.18 BC tests
Bytecode: re-enable -H with script/perlcc -B
Assembler: bump to 1.12
t/bytecode.t: use -H (again)

fixes tests 5.8 - 5.18
unTODO passing tests, fixed with 1.48 bytecode
C: bump to 1.48
CC: fix RV detection >5.12

B::Stackobj::Const::load_{int,double,str} should use the same
RV detection logic. RV changed with 5.12 to IV
C: print IVX as hex in Possible missing remap for compile-time XS symbol

Better have those pointers as hex, if only in the comment
unTODO B::Hooks::EndOfScope namespace::clean MooseX::Types > 5.19

module tests
t/modules: update 5.20-5.16
t/perldoc.t: simplified and unTODOd for all version

works now fine with -UB -uFile::Spec -uCwd, and -uExporter<5.10
Stackobj: bump to 1.12
t CORE--mro--isarev==BADTEST-353.t

change from SIG-0 to only test failures, tracked in #353