An unsupported naked function definition.
Erroneous code example:
#![feature(naked_functions)]
#[naked]
pub extern "C" fn f() -> u32 {
42
}The naked functions must be defined using a single inline assembly block.
The execution must never fall through past the end of the assembly
code so the block must use noreturn option. The asm block can also
use att_syntax and raw options, but others options are not allowed.
The asm block must not contain any operands other than const and
sym.
For more information, please see RFC 2972.