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

在 CPython 3.14 上重现多行条件表达式及其带括号的变体，然后跟踪 walrus 表达式的 parser 或语法错误位置处理。完成的标准是：插入符指向 if x := True 所在的行，同时带括号的情况仍能继续正确解析并报告其结果。