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/messages.ftl

@@ -44,8 +44,6 @@ codegen_ssa_ignoring_output = ignoring -o because multiple .{$extension} files w
 codegen_ssa_illegal_link_ordinal_format = illegal ordinal format in `link_ordinal`
     .note = an unsuffixed integer value, e.g., `1`, is expected
 
-codegen_ssa_incompatible_linking_modifiers = link modifiers combination `+bundle,+whole-archive` is unstable when generating rlibs
-
 codegen_ssa_insufficient_vs_code_product = VS Code is a different product, and is not sufficient.
 
 codegen_ssa_invalid_link_ordinal_nargs = incorrect number of arguments to `#[link_ordinal]`