Syntax errors for invalid 128-bit integer literals

[rymiel]

Fixes #10962

Since I am not skilled enough to resolve these TODOs in the codegen, I simply opted to warn about not being allowed to use literals larger than a 64-bit integer

crystal/src/compiler/crystal/codegen/codegen.cr

Lines 453 to 458 in 71d6e9b

	when :i128
	# TODO: implement String#to_i128 and use it
	@last = int128(node.value.to_i64)
	when :u128
	# TODO: implement String#to_u128 and use it
	@last = int128(node.value.to_u64)

[straight-shoota]

Thanks. Parser warnings are really fine for now. Full 128-bit support is a more complex story (#8373).

[Sija]

Missing indentation suggestions.

[sdogruyol]

Thank you @rymiel 🙏