hsail: fix unsigned offset bug in address calculation
hsail: fix unsigned offset bug in address calculation

it's possible for the offset provided to an HSAIL mem inst to be a negative
value, however the variable we use to hold the offset is an unsigned type.
this can lead to excessively large offset values when the offset is negative,
which will almost certainly cause the access to go out of bounds.

rallylee/gem5,TUD-OS/gem5-dtu,HwisooSo/gemV-update,rallylee/gem5,gem5/gem5,sobercoder/gem5,SanchayanMaity/gem5,SanchayanMaity/gem5,Weil0ng/gem5,gem5/gem5,SanchayanMaity/gem5,rjschof/gem5,TUD-OS/gem5-dtu,gem5/gem5,rjschof/gem5,SanchayanMaity/gem5,Weil0ng/gem5,rjschof/gem5,rallylee/gem5,sobercoder/gem5,powerjg/gem5-ci-test,TUD-OS/gem5-dtu,powerjg/gem5-ci-test,powerjg/gem5-ci-test,SanchayanMaity/gem5,KuroeKurose/gem5,rjschof/gem5,Weil0ng/gem5,SanchayanMaity/gem5,gem5/gem5,rallylee/gem5,HwisooSo/gemV-update,HwisooSo/gemV-update,HwisooSo/gemV-update,KuroeKurose/gem5,TUD-OS/gem5-dtu,HwisooSo/gemV-update,gedare/gem5,TUD-OS/gem5-dtu,sobercoder/gem5,gedare/gem5,Weil0ng/gem5,sobercoder/gem5,gem5/gem5,powerjg/gem5-ci-test,KuroeKurose/gem5,KuroeKurose/gem5,HwisooSo/gemV-update,KuroeKurose/gem5,KuroeKurose/gem5,TUD-OS/gem5-dtu,rjschof/gem5,gem5/gem5,SanchayanMaity/gem5,gedare/gem5,Weil0ng/gem5,KuroeKurose/gem5,HwisooSo/gemV-update,gedare/gem5,sobercoder/gem5,gedare/gem5,TUD-OS/gem5-dtu,Weil0ng/gem5,gem5/gem5,rallylee/gem5,sobercoder/gem5,powerjg/gem5-ci-test,Weil0ng/gem5,powerjg/gem5-ci-test,rjschof/gem5,powerjg/gem5-ci-test,rjschof/gem5,sobercoder/gem5,rallylee/gem5,gedare/gem5,rallylee/gem5,gedare/gem5