[IR] Update comment in Verifier::visitPHINode

Since svn r133708 visitPHINode no longer has to check basic block
argument types. Better 13 years late than never!

Author: jayfoad

llvm/lib/IR/Verifier.cpp

@@ -3381,7 +3381,7 @@ void Verifier::visitPHINode(PHINode &PN) {
   Check(!PN.getType()->isTokenTy(), "PHI nodes cannot have token type!");
 
   // Check that all of the values of the PHI node have the same type as the
-  // result, and that the incoming blocks are really basic blocks.
+  // result.
   for (Value *IncValue : PN.incoming_values()) {
     Check(PN.getType() == IncValue->getType(),
           "PHI node operands are not the same type as the result!", &PN);