Use the correct platform toolchain folder... (#58416)
Use the correct platform toolchain folder... (#58416)

...when bootstrapping with hosttools.

This would align with how the SDK path is calculated.

Addresses rdar://92298536
ahoppen/swift,JGiola/swift,benlangmuir/swift,benlangmuir/swift,roambotics/swift,apple/swift,ahoppen/swift,atrick/swift,ahoppen/swift,glessard/swift,JGiola/swift,roambotics/swift,roambotics/swift,roambotics/swift,apple/swift,glessard/swift,roambotics/swift,glessard/swift,apple/swift,benlangmuir/swift,apple/swift,roambotics/swift,atrick/swift,atrick/swift,benlangmuir/swift,JGiola/swift,atrick/swift,benlangmuir/swift,JGiola/swift,apple/swift,benlangmuir/swift,apple/swift,JGiola/swift,glessard/swift,glessard/swift,glessard/swift,ahoppen/swift,ahoppen/swift,atrick/swift,ahoppen/swift,JGiola/swift,atrick/swift