chore, only define alibi definition of _bextr_u32() when AVX2 isn't available

Signed-off-by: Sebastian Freundt <freundt@ga-group.nl>
hygiene, factor out classifying+bittifying into clittify()

Signed-off-by: Sebastian Freundt <freundt@ga-group.nl>
hygiene, abstract over actual accumulator type and its bitwidth

Signed-off-by: Sebastian Freundt <freundt@ga-group.nl>
fix, PEBKAC, set offset to end of array for unfindable streak in find_strk()

Signed-off-by: Sebastian Freundt <freundt@ga-group.nl>
fix, PEBKAC, get the logic right to fill up accu buffers in clittify()

Signed-off-by: Sebastian Freundt <freundt@ga-group.nl>
hygiene, mark clittify() as inline

Signed-off-by: Sebastian Freundt <freundt@ga-group.nl>
Merge branch 'tool/fastterms'

* tool/fastterms:
  hygiene, mark clittify() as inline
  fix, PEBKAC, get the logic right to fill up accu buffers in clittify()
  fix, PEBKAC, set offset to end of array for unfindable streak in find_strk()
  hygiene, abstract over actual accumulator type and its bitwidth
  hygiene, factor out classifying+bittifying into clittify()
  chore, only define alibi definition of _bextr_u32() when AVX2 isn't available