Implement bytecode-only runtime build mode

[yumin-chen]

Implement a bytecode-only runtime build mode that allows dead-stripping the parser and compiler from the generated binary when parser-dependent features are disabled. This involves guarding core entry points in quickjs.c and quickjs-libc.c, implementing automatic library selection in qjsc, and adding the necessary build system support and tests.

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PR created automatically by Jules for task 7784769475260091224 started by @yumin-chen

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[yumin-chen]

Add comprehensive tests that:

1. ensure BigInt, closures with mutation, generators, async/await, Map/Set iteration still work
2. test std.evalScript, std.loadScript, std.parseExtJSON are absent from the std module at runtime
3. test os.Worker is absent from the os module at runtime
4. test Function.prototype.toString() on a bytecode function
5. test of import.meta.url on a pre-compiled module
6. test that the bytecode-only binary rejects a partial/corrupted bytecode buffer gracefully

[yumin-chen]

And the following must not be guarded (as they are required for bytecode execution):

JS_ReadObject
JS_EvalFunction
JS_EvalFunctionInternal
free_function_bytecode
js_closure