[Triton-MLIR] Replace triton.extract_slice with tensor.extract_slice and support more general tensor slicing (#837)

## Features

- Allow taking a block of tensor slice, as long as each dimension is
contiguous (unit stride).
- Fix some problems in `insert_slice_async`'s semantic.
- More general verification for ops that return shared layout encoding.

## Known Limitations

- `insert_slice_async` still uses the old semantic. May submit another
PR later to support similar semantic like `tensor.extract_slice`.
- No encoding verification for `tensor.extract_slice`.
- 3d tensor ops are broken.
- Strided accesses are not allowed.
- May cause a little performance slowdown since we are passing strides
as values but not constants (e.g., int).
It would be difficult to pass strides as attributes when we have control
flows. A block argument is possible to accept tensors with different
strides.

lib/Analysis/Utility.cpp

@@ -24,7 +24,8 @@ bool maybeSharedAllocationOp(Operation *op) {
               mlir::TypeID::get<triton::gpu::TritonGPUDialect>() ||
           dialect->getTypeID() == mlir::TypeID::get<triton::TritonDialect>() ||
           dialect->getTypeID() ==
-              mlir::TypeID::get<arith::ArithmeticDialect>());
+              mlir::TypeID::get<arith::ArithmeticDialect>() ||
+          dialect->getTypeID() == mlir::TypeID::get<tensor::TensorDialect>());
 }
 
 std::string getValueOperandName(Value value, AsmState &state) {