[selectiondag] Check PromotedFloats map during expansive checks.

[fhahn]

Summary

PromotedFloats needs to be checked in
DAGTypeLegalizer::PerformExpensiveChecks. This patch fixes a few type
legalization failures with expansive checks for ARM fp16 tests.

[arsenm]

LGTM

lib/CodeGen/SelectionDAG/LegalizeTypes.cpp

for (unsigned i = 0, e = Node.getNumValues(); i != e; ++i) {
       if (ExpandedIntegers.find(Res) != ExpandedIntegers.end())
         Mapped |= 16;
       if (ExpandedFloats.find(Res) != ExpandedFloats.end())
         Mapped |= 32;
       if (SplitVectors.find(Res) != SplitVectors.end())
         Mapped |= 64;
       if (WidenedVectors.find(Res) != WidenedVectors.end())
         Mapped |= 128;
+      if (PromotedFloats.find(Res) != PromotedFloats.end())
+        Mapped |= 256;
 
       if (Node.getNodeId() != Processed) {
         // Since we allow ReplacedValues to map deleted nodes, it may map nodes
         // marked NewNode too, since a deleted node may have been reallocated as
         // another node that has not been seen by the LegalizeTypes machinery.
         if ((Node.getNodeId() == NewNode && Mapped > 1) ||
             (Node.getNodeId() != NewNode && Mapped != 0)) {
           dbgs() << "Unprocessed value in a map!";
for (unsigned i = 0, e = Node.getNumValues(); i != e; ++i) {
         if (Mapped & 16)
           dbgs() << " ExpandedIntegers";
         if (Mapped & 32)
           dbgs() << " ExpandedFloats";
         if (Mapped & 64)
           dbgs() << " SplitVectors";
         if (Mapped & 128)
           dbgs() << " WidenedVectors";
+        if (Mapped & 256)
+          dbgs() << " PromotedFloats";
         dbgs() << "\n";
         llvm_unreachable(nullptr);
       }
     }
   }
 
   // Checked that NewNodes are only used by other NewNodes.
   for (unsigned i = 0, e = NewNodes.size(); i != e; ++i) {