Revert "[NFC] Remote TODO regarding opaque ptr conversion"

This reverts commit d56eb82.

Author: pmatos

llvm/include/llvm/IR/Type.h

@@ -482,6 +482,9 @@ class Type {
   //===--------------------------------------------------------------------===//
   // Convenience methods for getting pointer types.
   //
+
+  // TODO: After opaque pointer transition this can be replaced by simply
+  //       calling PointerType::get(C, AS).
   static PointerType *getInt8PtrTy(LLVMContext &C, unsigned AS = 0);
 
   static Type *getWasm_ExternrefTy(LLVMContext &C);