C++: Delete unused predicate

Author: aschackmull

cpp/ql/lib/semmle/code/cpp/ir/dataflow/internal/SsaInternals.qll

@@ -1064,11 +1064,6 @@ module SsaCached {
     SsaImpl::lastRefRedefExt(def, sv, bb, i, input, next)
   }
 
-  cached
-  DefinitionExt phiHasInputFromBlockExt(PhiNode phi, IRBlock bb) {
-    SsaImpl::phiHasInputFromBlockExt(phi, result, bb)
-  }
-
   cached
   predicate ssaDefReachesReadExt(SourceVariable v, DefinitionExt def, IRBlock bb, int i) {
     SsaImpl::ssaDefReachesReadExt(v, def, bb, i)