stage2: Inferring the type of chained ifs differ in behavior between stage1 and 2

[Hejsil]

Zig Version

0.10.0-dev.2803+c248af3bd

Steps to Reproduce

// test.zig
const std = @import("std");

const testing = std.testing;

test {
    var a = false;
    var b = false;
    const name = if (a)
        "ab"
    else if (b)
        return error.TestFailed
    else
        null;
    try testing.expect(name == null);
}

$ stage1/zig test test.zig
$ stage2/zig test test.zig

Expected Behavior

I would expect the stage2 compiler to figure this out in the same way, stage1 does.

Actual Behavior

$ stage2/zig test test.zig
test.zig:10:10: error: value with comptime only type '@TypeOf(null)' depends on runtime control flow
    else if (b)
         ^
test.zig:10:14: note: runtime control flow here
    else if (b)