Consistently initialize clang CodeGenOptions.DebugTypeExtRefs
Consistently initialize clang CodeGenOptions.DebugTypeExtRefs

on all code paths. This flag is part of the Clang module hash. Setting it on all
paths makes it easier to reason about the permutations of Clang modules that are
being built on behalf of Swift.

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