Add a new select_value instruction. This instruction should be the equivalent of select_enum, just for builtin int types. Such an instruction is needed e.g. to efficiently implement conversions of Int raw values to C-like enums.

rdar://18812325

Swift SVN r23036

lib/SILAnalysis/ValueTracking.cpp

@@ -129,6 +129,7 @@ static bool isTransitiveEscapeInst(SILInstruction *Inst) {
   case ValueKind::RefToUnownedInst:
   case ValueKind::SelectEnumInst:
   case ValueKind::SelectEnumAddrInst:
+  case ValueKind::SelectValueInst:
   case ValueKind::StructElementAddrInst:
   case ValueKind::StructExtractInst:
   case ValueKind::StructInst: