Skip javascriptcore's first parse step for ES Modules

[pfgithub]

First half of #7384. Does not fix that problem, but gets closer to fixing it.

This pr:

• Adds a test to prepare for when 7384 is fixed (marked with {todo: true} (Adds support to mark a test file as --todo with {todo: "true"} #15633)
• Constructs ModuleInfo when printing with all the information needed to create a JavaScriptCore JSModuleRecord
• Replaces javascriptcore's first parsing step to generate the module record with our own generated module record
• Adds an env var COMPILE_ERRORS_ONLY=1 bun run build for building bun that skips codegen. This shows errors ~50% faster and can often reveal an error that was crashing zig previously

TODO:

• Make sure memory is freed in the case where the module is discarded before it is loaded?

Check:

• Make sure cached ModuleInfo in RuntimeTranspilerCache is used
• Test all the types of module imports and exports and re-exports and star exports and make sure they still work
• Consider whether to run the module_info building as a seperate pass at the end of printAst rather than integrating it into js_printer
• Consider using Ast.import records, export records, scope, ... to find the needed items rather than finding them in printer. There are a few special cases like the jest thing (but maybe could be solved by moving that transformation to a step before printing?)
• Does setFromUtf8 need to be used? What happens if it is called on a bad string containing non-utf8 bytes? Is this unsafe? Is it faster to use a setFromAscii fn when possible?
• remove the eqlComptime("*default*") check somehow (either just remove it and it's fine or add special indexes for those)
• Is ModuleInfo information needed in standalone module graph? see: module_loader.zig line 2633

Performance impact:

• large file, with runtime transpiler cache: ~15% ± 1% faster (node is ~2x faster than bun at this)
• large file, without runtime transpiler cache: ~5% ± 1% faster
• large file with only one import: 12% faster with runtime transpiler cache, 5% faster without
• small file, with imports: ~1% ± 2% slower
• small file, without imports: ~1% ± 2% slower
• (todo) real-world imports

Benchmark

// genlarge.js
let large_export_top = "";
let large_export_bottom = "export {\n";
let large_import_top = "import {\n";
let large_import_bottom = `function expect(a, b, c) {
    if(b !== a || c !== b) throw new Error("failure");
}\n`;

for(let i = 0; i < 30_000; i++) {
    large_export_top += `export const _${i} = ${i};\n`;
    large_export_bottom += "    _"+i+" as _"+i+"_d,\n";
    large_import_top += `    _${i}, _${i}_d,\n`;
    large_import_bottom += `expect(${i}, _${i}, _${i}_d);\n`;
}
large_export_bottom += "};\n";
large_import_top += "} from './large2.js';\n"

await Bun.write("large2.js", large_export_top + large_export_bottom);
await Bun.write("large.js", large_import_top + large_import_bottom);

// small.js
import { b } from "./small2.js";

console.log(b);

// small2.js
export const b = "abc";

// noimports.js
console.log("wow, no imports");

// runbench.js
const cmds = [
    "./bun-15758",
    "./bun-main",
];
const targets = [
    "./large.js woutrtc",
    "./large.js withrtc",
    "./largeni.js woutrtc",
    "./largeni.js withrtc",
    "./small.js",
    "./noimports.js",
];
for(const target of targets) {
    console.log("\n\n\nrunning benchmark:", target);
    await Bun.spawnSync({
        cmd: ["hyperfine", ...cmds.map(cmd => cmd + " " + target), "--warmup=5", "--shell=none"],
        env: {
            BUN_RUNTIME_TRANSPILER_CACHE_PATH: target.includes("withrtc") ? process.env.PWD + "/.rtc" : "0",
        },
        stdio: ["inherit", "inherit", "inherit"],
    });
}

// genlargeni.js
let large_export = "export const m = 25;\n";
let large_import = "import { m, n } from './largeni2.js';\n";
large_import += "console.log(m, n);\n";

for(let i = 0; i < 30_000; i++) {
    large_export += "console.log(1);\n";
    large_import += "console.log(1);\n";
}
large_export += "export const n = 25;\n";

await Bun.write("largeni2.js", large_export);
await Bun.write("largeni.js", large_import);

Run benchmark:

bun genlarge.js
bun genlargeni.js
bun runbench.js

[robobun]

^{Updated 4:12 PM PT - Jan 9th, 2025}

✅ @pfgithub, your commit 3daed8d has passed in #9326! 🎉

---

🧪   try this PR locally:

bunx bun-pr 15758