AUIPCC fast representability check differs from the spec

[PeterRugg]

As reported by Dapeng Gao:

The Flute implementation (

Flute/src_Core/CPU/EX_ALU_functions.bsv

Line 820 in 8f7f582

if (getFlags(toCapPipe(inputs.pcc))[0] == 1'b1) begin

) is internally performing a SET_OFFSET operation instead of a SET_ADDR operation as required in the ISAv8 report (page 284), and due to the imprecise comparison of the fast representability check, the tag of the resulting capability is sometimes cleared when it shouldn’t.