Short echo syntax cannot be used as an identifier
-----
<?php
class C {
    use T {
        x as y?><?= as my_echo;
    }
}
-----
Cannot use "<?=" as an identifier from 4:17 to 4:19
array(
    0: Stmt_Class(
        attrGroups: array(
        )
        flags: 0
        name: Identifier(
            name: C
        )
        extends: null
        implements: array(
        )
        stmts: array(
            0: Stmt_TraitUse(
                traits: array(
                    0: Name(
                        name: T
                    )
                )
                adaptations: array(
                    0: Stmt_TraitUseAdaptation_Alias(
                        trait: null
                        method: Identifier(
                            name: x
                        )
                        newModifier: null
                        newName: Identifier(
                            name: y
                        )
                    )
                    1: Stmt_TraitUseAdaptation_Alias(
                        trait: null
                        method: Identifier(
                            name: <?=
                        )
                        newModifier: null
                        newName: Identifier(
                            name: my_echo
                        )
                    )
                )
            )
        )
    )
)