Encapsed string negative var offsets
-----
<?php
"$a[-0]";
"$a[-1]";
"$a[-0x0]";
"$a[-00]";
"$a[@@{ -PHP_INT_MAX - 1 }@@]";
-----
!!php7
array(
    0: Stmt_Expression(
        expr: Scalar_Encapsed(
            parts: array(
                0: Expr_ArrayDimFetch(
                    var: Expr_Variable(
                        name: a
                    )
                    dim: Scalar_String(
                        value: -0
                    )
                )
            )
        )
    )
    1: Stmt_Expression(
        expr: Scalar_Encapsed(
            parts: array(
                0: Expr_ArrayDimFetch(
                    var: Expr_Variable(
                        name: a
                    )
                    dim: Scalar_LNumber(
                        value: -1
                    )
                )
            )
        )
    )
    2: Stmt_Expression(
        expr: Scalar_Encapsed(
            parts: array(
                0: Expr_ArrayDimFetch(
                    var: Expr_Variable(
                        name: a
                    )
                    dim: Scalar_String(
                        value: -0x0
                    )
                )
            )
        )
    )
    3: Stmt_Expression(
        expr: Scalar_Encapsed(
            parts: array(
                0: Expr_ArrayDimFetch(
                    var: Expr_Variable(
                        name: a
                    )
                    dim: Scalar_String(
                        value: -00
                    )
                )
            )
        )
    )
    4: Stmt_Expression(
        expr: Scalar_Encapsed(
            parts: array(
                0: Expr_ArrayDimFetch(
                    var: Expr_Variable(
                        name: a
                    )
                    dim: Scalar_LNumber(
                        value: @@{ -PHP_INT_MAX - 1 }@@
                    )
                )
            )
        )
    )
)