[CIR] Un-xfail variadic calls

[AdUhTkJm]

This un-xfails the 6 files in #1497 related to variadic calls.

[FantasqueX]

clangir/clang/lib/CIR/Dialect/IR/CIRDialect.cpp

Lines 2346 to 2351 in 8cb8395

	// Parse the function signature.
	bool isVariadic = false;
	if (function_interface_impl::parseFunctionSignature(
	parser, /*allowVariadic=*/true, arguments, isVariadic, resultTypes,
	resultAttrs))
	return failure();

This parameter was true before rebasing. It's a mistake during rebase.

[FantasqueX]

LGTM