rust: Fix build failure when multilibs are enabled

When multilibs are enabled, rustc could not find dynamic libraries in the
lib64 directory due to the bootstrapping process searching in the lib
directory. This commit exports both lib and lib64 paths to ensure
correct library detection.

dropped:
revert-Zdual-proc-macros-additional-check.patch

We reverted the previous commit to prevent errors when rustc cannot find
dynamic libraries. Since the issue has been resolved by exporting the
lib paths, this revert is no longer necessary, as it won't cause any
errors moving forward.

Signed-off-by: Deepesh Varatharajan <Deepesh.Varatharajan@windriver.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>

Author: Deepesh Varatharajan

meta/recipes-devtools/rust/files/revert-Zdual-proc-macros-additional-check.patch

@@ -7,7 +7,6 @@ SRC_URI += "https://static.rust-lang.org/dist/rustc-${RUST_VERSION}-src.tar.xz;n
             file://oeqa-selftest-Increase-timeout-in-process-sigpipe-ru.patch;patchdir=${RUSTSRC} \
             file://0001-src-core-build_steps-tool.rs-switch-off-lto-for-rust.patch;patchdir=${RUSTSRC} \
 	    file://revert-link-std-statically-in-rustc_driver-feature.patch;patchdir=${RUSTSRC} \
-	    file://revert-Zdual-proc-macros-additional-check.patch;patchdir=${RUSTSRC} \
 "
 SRC_URI[rust.sha256sum] = "7b11d4242dab0921a7d54758ad3fe805153c979c144625fecde11735760f97df"
 

meta/recipes-devtools/rust/rust-source.inc

@@ -223,6 +223,9 @@ rust_runx () {
 
     oe_cargo_fix_env
 
+    # When multilibs are enabled, rustc can't find dynamic libraries in "lib64" because the bootstrapping process looks in "lib". To fix this, export both paths:
+    export LD_LIBRARY_PATH=${S}/build/${RUST_BUILD_SYS}/stage1/lib:${S}/build/${RUST_BUILD_SYS}/stage1/lib64:$LD_LIBRARY_PATH
+
     python3 src/bootstrap/bootstrap.py ${@oe.utils.parallel_make_argument(d, '-j %d')} "$@" --verbose
 }
 rust_runx[vardepsexclude] += "PARALLEL_MAKE"