[MLIR] Change Operation::create() methods to use Value/Type/Block ranges.

- Introduce a new BlockRange class to represent range of blocks (constructible from
  an ArrayRef<Block *> or a SuccessorRange);
- Change Operation::create() methods to use TypeRange for result types, ValueRange for
  operands and BlockRange for successors.

Differential Revision: https://reviews.llvm.org/D86985