[Fix][TVMScript] Parse and print tir_vars of call_tir properly

[MasterJH5574]

This PR patches both the TVMScript parser and printer on handling the tir_vars parameter of call_tir.

When a TIR function contains symbolic shapes, its signature can have trailing TIR vars in the param list. In such cases, when using call_tir to call into the TIR function, we should provide the instances of those TIR vars through the param tir_vars. tir_vars is the last parameter of call_tir, one behind dtype.

relax/python/tvm/relax/op/base.py

Lines 45 to 51 in 697675b

	def call_tir(
	func: Union[str, Expr],
	args: Union[Expr, List[Expr]],
	shape: Union[RxTuple, ShapeExpr, List[int]],
	dtype: Union[str, List[str]],
	tir_vars: Optional[ShapeExpr] = None,
	) -> Call:

The specific issues fixed in this PR is:

• Printer: prior to this PR, when printing call_tir, the printer always explicitly prints "dtype=", while doesn’t print "tir_vars=" when there is. This will make the printed script looks like

  y = R.call_tir(copy, (x,), ((n * 2,)), dtype="float32", (n,))

  which doesn’t conform to Python syntax.
• call_tir’s handling on TIR vars: the TIR vars will be parsed as a list or a tuple of Python, while on the call_tir side the parsed tuple/list will be treated as a Expr and passed to C++ side through FFI. This will incur FFI error like

  error:   Check failed: (!checked_type.defined()) is false: Expected RelayExpr, but got Array
  

Therefore, this PR fixes both sides. On printer side, we now print tir_vars after dtype and explicitly print "tir_vars=". On call_tir side, we wrap the input tir_vars to ShapeExpr if we find it a tuple or list. One regression test that covers both issues is provided.

cc @YuchenJin

[YuchenJin]

LGTM!