TableGen: Add strict assertions to sanity check earlier type checking

[nhaehnle]

Summary

Both of these errors should have been caught by type-checking during
parsing.

Change-Id: I891087936fd1a91d21bcda57c256e3edbe12b94d

llvm/trunk/include/llvm/TableGen/Record.h

public:
 
   bool getPrefix() const { return TyAndPrefix.getInt(); }
   RecTy *getType() const { return TyAndPrefix.getPointer(); }
   Init *getValue() const { return Value; }
 
   bool setValue(Init *V) {
     if (V) {
       Value = V->convertInitializerTo(getType());
+      assert(!Value || !isa<TypedInit>(Value) ||
+             cast<TypedInit>(Value)->getType()->typeIsConvertibleTo(getType()));
       return Value == nullptr;
     }
     Value = nullptr;
     return false;
   }
 
   void dump() const;
   void print(raw_ostream &OS, bool PrintSem = true) const;

llvm/trunk/lib/TableGen/Record.cpp

ListInit *ListInit::get(ArrayRef<Init *> Range, RecTy *EltTy) {
 
   FoldingSetNodeID ID;
   ProfileListInit(ID, Range, EltTy);
 
   void *IP = nullptr;
   if (ListInit *I = ThePool.FindNodeOrInsertPos(ID, IP))
     return I;
 
+  assert(Range.empty() || !isa<TypedInit>(Range[0]) ||
+         cast<TypedInit>(Range[0])->getType()->typeIsConvertibleTo(EltTy));
+
   void *Mem = Allocator.Allocate(totalSizeToAlloc<Init *>(Range.size()),
                                  alignof(ListInit));
   ListInit *I = new(Mem) ListInit(Range.size(), EltTy);
   std::uninitialized_copy(Range.begin(), Range.end(),
                           I->getTrailingObjects<Init *>());
   ThePool.InsertNode(I, IP);
   return I;
 }