[nfc][cxx-interop] Fix regex in reference irgen test.
[nfc][cxx-interop] Fix regex in reference irgen test.

We shouldn't rely on the specific name of the operand.

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