* Add Pmull_V Sse fast path only, both "8/16B -> 8H" and "1/2D -> 1Q" variants; with Test.
* Add Clmul fast path for the 128 bits variant.
* Small optimisation (save 60 instructions) for the Sse fast path about the 128 bits variant.
* Add slow path, both variants. Fix V128 Shl/Shr when shift = 0.
* A32: Add Vmull_I P64 variant (slow path); not tested.
* A32: Add Vmull_I_P8_P64 Test and fix P64 variant.
