Remove bounds checking for table lookup

[newhoggy]

Before

$ time hw-xml create-index --input psd7003.xml --ib-output psd7003.xml.ib.idx --bp-output psd7003.xml.bp.idx --method stream
hw-xml create-index --input psd7003.xml --ib-output psd7003.xml.ib.idx      31.22s user 3.83s system 219% cpu 15.978 total
$ time hw-xml create-index --input psd7003.xml --ib-output psd7003.xml.ib.idx --bp-output psd7003.xml.bp.idx --method stream
hw-xml create-index --input psd7003.xml --ib-output psd7003.xml.ib.idx      30.80s user 3.86s system 217% cpu 15.926 total
$ time hw-xml create-index --input psd7003.xml --ib-output psd7003.xml.ib.idx --bp-output psd7003.xml.bp.idx --method stream
hw-xml create-index --input psd7003.xml --ib-output psd7003.xml.ib.idx      30.12s user 3.68s system 213% cpu 15.812 total

After

$ time hw-xml create-index --input psd7003.xml --ib-output psd7003.xml.ib.idx --bp-output psd7003.xml.bp.idx --method stream
hw-xml create-index --input psd7003.xml --ib-output psd7003.xml.ib.idx      27.59s user 3.41s system 226% cpu 13.666 total
$ time hw-xml create-index --input psd7003.xml --ib-output psd7003.xml.ib.idx --bp-output psd7003.xml.bp.idx --method stream
hw-xml create-index --input psd7003.xml --ib-output psd7003.xml.ib.idx      27.46s user 3.57s system 224% cpu 13.799 total
$ time hw-xml create-index --input psd7003.xml --ib-output psd7003.xml.ib.idx --bp-output psd7003.xml.bp.idx --method stream
hw-xml create-index --input psd7003.xml --ib-output psd7003.xml.ib.idx      29.24s user 3.96s system 229% cpu 14.458 total