Incorrect SyntaxError location for walrus operator in multi-line conditional expression

Bug report

Bug description:

When using the walrus operator (:=) inside a multi-line conditional expression, Python raises a SyntaxError with the error position pointing to the wrong location.
The caret (^) is shown under the expression body instead of the if clause where the syntax issue actually occurs, making debugging misleading.
The error indicator should instead highlight the if portion (or walrus usage context), not the preceding expression line.

Code

(
    1
    if x := True
    else 2
)

Traceback

File "[REDACTED]", line 2
    1
    ^
SyntaxError: expected 'else' after 'if' expression

It locates error to 1 but it should have located to if x := True (line no. 3)

It does not errors when condition is parenthesized:

(
    1
    if (x := True)
    else 2
)  # output: 1

CPython versions tested on:

3.14

Operating systems tested on:

Linux

Linked PRs

• gh-146305

CPython 3.14 で複数行の条件式とその括弧付きのバリエーションを再現し、続いて walrus 式の parser または構文エラー位置の処理を追跡します。括弧付きの場合は引き続き正しく解析されて結果を報告し、キャレットが if x := True の行を指すようになれば完了です。