ARM platforms. This patch resolves this issue and unifies AUX column
processing at x86 and ARM using tempate class SimdProcessor.
The patch also replaces uint16_t mask previously used in column.cpp and
SimProcessor code with a native masks that platform uses, e.g. __m128i
or __m128 on x86 and variety of masks on ARM.
To unify the processing I introduced a new filtering Compare Operator - COMPARE_NULLEQ.
with a 'c1 IS NULL semantics'.
Short CHAR/VARCHAR column values contain integer-encoded strings.
After certain manipulations(orderSwap(strnxfrm(str))) the values
become integers that preserve original strings order relation
according to a certain translation rules(collation). Prepared
values are ready to be SIMD-processed.
