x86_64 codegen missing lret{,q} instruction

[Noodlez1232]

Zig Version

0.15.1

Steps to Reproduce and Observed Behavior

Create a zig file called reproduce.zig.

// Should not run on OS systems, but should compile
pub fn main() !void {
    const sel: u64 = 0x80;
    // Should load the segment selector 0x80 into CS
    asm volatile (
        \\ push %[sel]
        \\ lea finish(%%rip), %%rax
        \\ push %%rax
        \\ lretq
        \\ finish:
        :
        : [sel] "r" (sel),
        : .{ .rax = true });
}

zig build-exe reproduce.zig

$ zig build-exe reproduce.zig 
reproduce.zig:1:5: error: invalid mnemonic: 'lretq'
pub fn main() !void {
~~~~^~~~~~~~~~~~~~~

Expected Behavior

Inline assembly assembles