Support weight-compressed date type s8

[usstq]

Description

Inner-product with symmetrically quantized/compressed weight may have s8 as weight data type (it saves the zero-point subtraction cost), this change added support to such weight dt.

Fixes # (github issue)

Checklist

General

• [ ] Do all unit and benchdnn tests (make test and make test_benchdnn_*) pass locally for each commit?
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Performance improvements

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New features

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Bug fixes

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RFC PR

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