GSB: Relax verify check some more in RequirementSignatureRequest
GSB: Relax verify check some more in RequirementSignatureRequest

The GSB sometimes emits redundant same-type requirements here. Only
checking for a prefix would still trigger false positives, so relax
it all the way to only consider conformance requirements, which
are the important ones from an ABI standpoint.

atrick/swift,benlangmuir/swift,glessard/swift,rudkx/swift,ahoppen/swift,rudkx/swift,glessard/swift,JGiola/swift,benlangmuir/swift,atrick/swift,gregomni/swift,gregomni/swift,apple/swift,benlangmuir/swift,glessard/swift,benlangmuir/swift,rudkx/swift,gregomni/swift,ahoppen/swift,atrick/swift,benlangmuir/swift,ahoppen/swift,glessard/swift,ahoppen/swift,roambotics/swift,apple/swift,apple/swift,JGiola/swift,rudkx/swift,atrick/swift,roambotics/swift,ahoppen/swift,atrick/swift,gregomni/swift,atrick/swift,rudkx/swift,rudkx/swift,apple/swift,benlangmuir/swift,JGiola/swift,roambotics/swift,glessard/swift,gregomni/swift,JGiola/swift,roambotics/swift,gregomni/swift,roambotics/swift,glessard/swift,apple/swift,JGiola/swift,roambotics/swift,apple/swift,JGiola/swift,ahoppen/swift