Rollup merge of #132732 - gavincrawford:as_ptr_attribute, r=Urgau

Use attributes for `dangling_pointers_from_temporaries` lint

Checking for dangling pointers by function name isn't ideal, and leaves out certain pointer-returning methods that don't follow the `as_ptr` naming convention. Using an attribute for this lint cleans things up and allows more thorough coverage of other methods, such as `UnsafeCell::get()`.

compiler/rustc_span/src/symbol.rs

@@ -316,6 +316,7 @@ symbols! {
         SubdiagMessage,
         Subdiagnostic,
         Sync,
+        SyncUnsafeCell,
         T,
         Target,
         ToOwned,
@@ -409,7 +410,6 @@ symbols! {
         arm,
         arm_target_feature,
         array,
-        as_mut_ptr,
         as_ptr,
         as_ref,
         as_str,
@@ -1655,6 +1655,7 @@ symbols! {
         rustc_allow_const_fn_unstable,
         rustc_allow_incoherent_impl,
         rustc_allowed_through_unstable_modules,
+        rustc_as_ptr,
         rustc_attrs,
         rustc_autodiff,
         rustc_box,