remove commented-out returned SV code, introduce split_head
bug fixes, optimizing, WIN32_API_DEBUG GCC, alloca/memcpy replced MSVC 32b

-changed profiling timing code to be cumulative and added CPU locking
-added a bypass of looking inside cv on ->Call() by making cv a tagged ptr
-an optimized MASM inline asbsembly replaced alloca and memcpy on x86-32
-returning a MI64 obj became branchless between signed and unsigned MI64s
-in commit "further optimizations in incoming arg loop, TARG usage, no
 memcpy" a loop overflow was introduced, depending on uninit memory,
 this could lead to a junk SV * on Perl stack being accessed
-in commit "further optimizations in incoming arg loop, TARG usage,
 no memcpy", a bug that make native unsigned I64s signed scalars, has
 been fixed
-in call_i686.h, a bug with T_INTEGER not being in a switch under
 WIN32_API_DEBUG was fixed, originally T_INTEGER was changed at Call()
 runtime to another T_ code in Call(), but that changing of T_ code was
 removed as an optimization
-some compiler warnings silenced
-random optimizing
-see Changes