workaround to support i686 + clang 5.0+

clang version 5.0.0 (http://root.cern.ch/git/clang.git 354b25b5d915ff3b1946479ad07f3f2768ea1621) (http://root.cern.ch/git/llvm.git 9c749361ba8c2d400b83d8cc5c544287465b7489)
Target: i686-pc-linux-gnu
Thread model: posix

rustup 1.23.1 (3df2264a9 2020-11-30)

rustc 1.53.0-nightly (d0695c908 2021-04-12)

tools/rust-lld-wrapper

@@ -43,7 +43,12 @@ def find_rust_lld():
     bin_path = path.dirname(rustc_path)
     rust_lld_path = path.join(bin_path, "../lib/rustlib/x86_64-unknown-linux-gnu/bin/rust-lld")
 
+    if path.isfile(rust_lld_path):
+        return rust_lld_path
+
+    rust_lld_path = path.join(bin_path, "../lib/rustlib/i686-unknown-linux-gnu/bin/rust-lld")
     assert path.isfile(rust_lld_path)
+
     return rust_lld_path
 
 main()