Broken JS_READ_OBJ_ROM_DATA flag

[bnoordhuis]

This JS_ReadObject() flag no longer works for bytecode. The IC opcodes introduced in #120 are patched during execution.

I can see a few solutions:

1. disable ICs when the bytecode buffer should be considered immutable

2. make a copy of the bytecode buffer in JS_ReadFunctionBytecode()

3. remove the flag

I'm leaning towards option 3 so if anyone is using the flag, now would be a good time to speak up. :-)

[saghul]

Agreed with option 3.