x86_64 backend `genSetReg called with a value larger than dst_reg`

[Beyley]

Zig Version

0.13.0-dev.340+d750a78b2

Steps to Reproduce and Observed Behavior

git clone the repo https://github.com/Beyley/zishzingers at commit 58cd6ebcd4bd0dcaddac70ef6c0cc9a947af3f43
build with zig build -Duse_llvm=false on a linux host

receive the error

src/parser.zig:681:1: error: genSetReg called with a value larger than dst_reg
fn consumeClassStatement(self: *Self, class_modifiers: MMTypes.Modifiers) !void {
^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

Expected Behavior

app compiles as it does on LLVM backend

[jacobly0]

No longer reproduces.