Mark internal, hidden LLVMFuzzerTestOneInput LibFuzzer hook as unsafe

Fixes #112

Author: fitzgen

src/lib.rs

@@ -53,10 +53,11 @@ extern "C" {
     fn LLVMFuzzerMutate(data: *mut u8, size: usize, max_size: usize) -> usize;
 }
 
+/// Do not use; only for LibFuzzer's consumption.
 #[doc(hidden)]
 #[export_name = "LLVMFuzzerTestOneInput"]
-pub fn test_input_wrap(data: *const u8, size: usize) -> i32 {
-    let test_input = ::std::panic::catch_unwind(|| unsafe {
+pub unsafe fn test_input_wrap(data: *const u8, size: usize) -> i32 {
+    let test_input = ::std::panic::catch_unwind(|| {
         let data_slice = ::std::slice::from_raw_parts(data, size);
         rust_fuzzer_test_input(data_slice)
     });