stage2: comptime fields are not always checked for equality when initialized

[topolarity]

Zig Version

0.10.0-dev.2882+556f12174

Steps to Reproduce

This fails as expected:

test {
    const T = struct {
        comptime x: i32 = 0,
        comptime y: u8 = 123,
    };
    var a: T = .{.x = -1234, .y = 0};
    _ = a;
}

However, both of these currently compile when they should not:

pub const U = struct {
    comptime foo: u32 = 1,
    bar: u32,
};
fn foo(x: U) void {
    _ = x;
}
test {
    _ = foo(U{ .foo = 2, .bar = 2 });
}

test {
    var x: u32 = 15;
    const T = @TypeOf(.{ @as(i32, -1234), @as(u32, 5678), x });
    var a: T = .{ -1234, 5678, x + 1 };
    _ = a;
}

Expected Behavior

All three tests above should fail with the error message "value stored in comptime field does not match the default value of the field"

Actual Behavior

The second test compiles successfully. The third test panics due to generating a runtime store to a comptime field.