The previous commit changes Ripper lex state behavior of `tLABEL`.
For example, Ripper lex state for the second `bar` was changed
by the previous commit.
```
def foo(bar: bar())
end
```
Before the commit, Ripper didn’t add label `bar` id to `vtable`
because `formal_argument` function for Ripper didn’t return id
but returned `VALUE lhs`.
Therefore Ripper didn’t `SET_LEX_STATE(EXPR_END|EXPR_LABEL)` for following `bar`
in `parse_ident` because `lvar_defined` for following `bar` was not true.
Currently Ripper does `SET_LEX_STATE(EXPR_END|EXPR_LABEL)` then
the result of this test case is changed like below.
```
Prism::ParseTest#test_filepath_unparser/corpus/literal/def.txt [ruby/test/prism/parse_test.rb:280]:
<[[80, 13], :on_ident, “bar”, END|LABEL]> expected but was
<[[80, 13], :on_ident, “bar”, ARG]>.
```
Parser sets lex state to `END|LABEL` on master branch.
Therefore previous commit makes Ripper’s behavior aligned with parser’s behavior.
```
$ ruby -v -y -e "def foo(bar: bar())" -e "end"
ruby 3.4.0dev (2024-02-11T23:52:05Z master 697ade7bda) [arm64-darwin21]
...
Reading a token
parser_dispatch_scan_event:11210 (1: 12|1|7)
lex_state: ARG|LABELED -> ARG at line 11113
lex_state: ARG -> END|LABEL at line 11128
parser_dispatch_scan_event:11877 (1: 13|3|4)
Next token is token “local variable or method” (1.13-1.16: bar)
Shifting token “local variable or method” (1.13-1.16: bar)
```