`inline_call` and `inline_into_callers` should check if it inlines into the left side of a binary expression

[Veykril]

fn foo$0() -> u32 {
    let x = 0;
    x
}
fn bar() -> u32 {
    foo() + foo()
}

gives us

fn bar() -> u32 {
    {
        let x = 0;
        x
    } + {
        let x = 0;
        x
    }
}

which is invalid, as the first block will be parsed as a statement and as such we need to wrap the first block in () parentheses to force an expression parse.

cc #10352 (comment)