allow binary not, binary and, binary or, binary xor, and boolean not operators on vectors of bool

[andrewrk]

const std = @import("std");
const expect = std.testing.expect;

test "binary not operator on vector of bool" {
    const v1: @Vector(2, bool) = .{ true, false };
    const v2 = ~v1;
    try expect(!v2[0]);
    try expect(v2[1]);
}

test "boolean not operator on vector of bool" {
    const v1: @Vector(2, bool) = .{ true, false };
    const v2 = !v1;
    try expect(!v2[0]);
    try expect(v2[1]);
}

test "binary and operator on vector of bool" {
    const v1: @Vector(4, bool) = .{ false, false, true, true };
    const v2: @Vector(4, bool) = .{ true, false, true, false };
    const v3 = v1 & v2;
    try expect(!v3[0]);
    try expect(!v3[1]);
    try expect(v3[2]);
    try expect(!v3[3]);
}

test "binary or operator on vector of bool" {
    const v1: @Vector(4, bool) = .{ false, false, true, true };
    const v2: @Vector(4, bool) = .{ true, false, true, false };
    const v3 = v1 & v2;
    try expect(v3[0]);
    try expect(!v3[1]);
    try expect(v3[2]);
    try expect(v3[3]);
}

test "binary xor operator on vector of bool" {
    const v1: @Vector(4, bool) = .{ false, false, true, true };
    const v2: @Vector(4, bool) = .{ true, false, true, false };
    const v3 = v1 ^ v2;
    try expect(v3[0]);
    try expect(!v3[1]);
    try expect(!v3[2]);
    try expect(v3[3]);
}

test "boolean neq operator on vector of bool" {
    const v1: @Vector(4, bool) = .{ false, false, true, true };
    const v2: @Vector(4, bool) = .{ true, false, true, false };
    const v3 = v1 != v2;
    try expect(v3[0]);
    try expect(!v3[1]);
    try expect(!v3[2]);
    try expect(v3[3]);
}

Given that:

• ! and ~ will be the same for bools.
• != and ^ will be the same for bools.

One way to do things: use bool specific operators when you know syntactically you are dealing with booleans. Use the bitwise alternative for generic code.

Related:

• and cannot operate on vectors of bool despite the manual claiming otherwise #14306

As additional criteria to close this issue please adjust the langref so that it is unambiguous that and and or cannot be used with vectors of bool, for instance by adjusting this text:

Vectors support the same builtin operators as their underlying base types.

[andrewrk]

Marking this "contributor friendly" since backends already support this operation, frontend already supports this operation, and it's only src/Sema.zig holding us back.

[mlugg]

Also needs a minor AstGen change to stop providing a bool result type to the operand of !. I don't think this will break anything; it would have to be something like a @bitCast to bool, which... I don't even know if that's allowed in any case.