stage2 miscompilation involving vectors

[xxxbxxx]

Zig Version

0.10.0-dev.2895+3486d8dd2

Steps to Reproduce

const std = @import("std");

const Vec3 = @Vector(3, i32);

test {
    var arena_alloc = std.heap.ArenaAllocator.init(std.testing.allocator);
    defer arena_alloc.deinit();
    const arena = arena_alloc.allocator();

    var points = std.ArrayList(Vec3).init(arena);

    try points.append(Vec3{ 404, -588, -901 });
    try points.append(Vec3{ 528, -643, 409 });
    try points.append(Vec3{ -838, 591, 734 });
    try points.append(Vec3{ 390, -675, -793 });
    try points.append(Vec3{ -537, -823, -458 });
    try points.append(Vec3{ -485, -357, 347 });
    try points.append(Vec3{ -345, -311, 381 });
    try points.append(Vec3{ -661, -816, -575 });

    try std.testing.expectEqual(points.items[6], Vec3{ -345, -311, 381 });      // ok 

    // adding one more fails. (arraylist reallocs..)
    try points.append(Vec3{ -876, 649, 763 });
    try std.testing.expectEqual(points.items[6], Vec3{ -345, -311, 381 });      // fails
}

Expected Behavior

success

(and does with stage1)

Actual Behavior

Test [1/1] test_0... index 0 incorrect. expected -345, found -1431655766
Test [1/1] test_0... FAIL (TestExpectedEqual)

[andrewrk]

which target CPU architecture?

[xxxbxxx]

which target CPU architecture?

x86-64