Add support for unsafe extern blocks

Author: pvdrz

bindgen/codegen/mod.rs

@@ -800,8 +800,14 @@ impl CodeGenerator for Var {
                 quote! { mut }
             };
 
+            let safety = ctx
+                .options()
+                .rust_features
+                .unsafe_extern_blocks
+                .then(|| quote!(unsafe));
+
             let tokens = quote!(
-                extern "C" {
+                #safety extern "C" {
                     #(#attrs)*
                     pub static #maybe_mut #canonical_ident: #ty;
                 }
@@ -4704,9 +4710,16 @@ impl CodeGenerator for Function {
         let ret = utils::fnsig_return_ty(ctx, signature);
 
         let ident = ctx.rust_ident(ident);
+
+        let safety = ctx
+            .options()
+            .rust_features
+            .unsafe_extern_blocks
+            .then(|| quote!(unsafe));
+
         let tokens = quote! {
             #wasm_link_attribute
-            extern #abi {
+            #safety extern #abi {
                 #(#attributes)*
                 pub fn #ident ( #( #args ),* ) #ret;
             }

bindgen/features.rs

@@ -255,6 +255,9 @@ define_rust_targets! {
         ptr_metadata: #81513,
         layout_for_ptr: #69835,
     },
+    Stable_1_82(82) => {
+        unsafe_extern_blocks: #127921,
+    },
     Stable_1_77(77) => {
         offset_of: #106655,
         literal_cstr(2021)|(2024): #117472,