[Bug #19392] Make args connected with and/or as a body of method

[yui-knk]

def test = puts("foo") or puts("bar") is interrupted as def test = (puts("foo") or puts("bar")).

[Note] (2023-12-07) I created this patch to demonstrate it's not difficult to support this feature with LR parser generator. This doesn't mean I agree with the change.

[zverok]

Unfortunately, this PR doesn't fix if/unless problem (which, despite my ticket's initial contents, is more critical than and/or):

def foo(arg) = p("OK") if arg

foo(false)
foo(true)

This is expected (with "natural" for the author precedences) to print "OK" once, but instead it fails with

test.rb:1:in `<main>': undefined local variable or method `arg' for main (NameError)

Apparently, it is still interpreted as

(def foo(arg) = p("OK")) if arg

Would it be possible to handle in the same manner? 🙏