[mlir][IR] Remove references to BuiltinOps from IR/

[mlir][IR] Remove references to BuiltinOps from IR/

There isn't a good reason for anything within IR to specifically reference any of the builtin operations. The only place that had a good reason in the past was AsmPrinter, but the behavior there doesn't need to hardcode ModuleOp anymore.

Differential Revision: https://reviews.llvm.org/D92448