Fix a couple of 2018 edition warnings

Author: bjorn3

example/alloc_example.rs

@@ -18,7 +18,7 @@ extern "C" {
 }
 
 #[panic_handler]
-fn panic_handler(_: &core::panic::PanicInfo) -> ! {
+fn panic_handler(_: &core::panic::PanicInfo<'_>) -> ! {
     core::intrinsics::abort();
 }
 

example/mod_bench.rs

@@ -3,15 +3,15 @@
 
 #[cfg_attr(unix, link(name = "c"))]
 #[cfg_attr(target_env = "msvc", link(name = "msvcrt"))]
-extern {}
+extern "C" {}
 
 #[panic_handler]
-fn panic_handler(_: &core::panic::PanicInfo) -> ! {
+fn panic_handler(_: &core::panic::PanicInfo<'_>) -> ! {
     core::intrinsics::abort();
 }
 
-#[lang="eh_personality"]
-fn eh_personality(){}
+#[lang = "eh_personality"]
+fn eh_personality() {}
 
 // Required for rustc_codegen_llvm
 #[no_mangle]