stabilize combining +bundle and +whole-archive link modifiers

Currently, combining +bundle and +whole-archive works only with
 #![feature(packed_bundled_libs)]
This crate feature is independent of the -Zpacked-bundled-libs
command line option.

This commit stabilizes the #![feature(packed_bundled_libs)] crate
feature and implicitly enables it only when the +bundle and
+whole-archive link modifiers are combined. This allows rlib
crates to use the +whole-archive link modifier with native
libraries and have all symbols included in the linked library
to be included in downstream staticlib crates that use the rlib as
a dependency. Other cases requiring the packed_bundled_libs
behavior still require the -Zpacked-bundled-libs command line
option, which can be stabilized independently in the future.

Per discussion on https://github.com/rust-lang/rust/issues/108081
there is no risk of regression stabilizing the crate feature in
this way because the combination of +bundle,+whole-archive link
modifiers was previously not allowed.

compiler/rustc_codegen_ssa/src/base.rs

@@ -839,7 +839,6 @@ impl CrateInfo {
             dependency_formats: tcx.dependency_formats(()).clone(),
             windows_subsystem,
             natvis_debugger_visualizers: Default::default(),
-            feature_packed_bundled_libs: tcx.features().packed_bundled_libs,
         };
         let crates = tcx.crates(());