Fixes multilib: %LIB_DIR% is substituted by the ebuild after PATCHES are
applied (see src_prepare). ROCm is the only branch that needs it -- the CUDA
and CPU branches derive lib_dir in Python.

Rebased for 2.14.0, where the 2.10.0 patch applied only with fuzz 2.
--- a/torch/utils/cpp_extension.py
+++ b/torch/utils/cpp_extension.py
@@ -1786,10 +1786,10 @@
         paths.extend([TORCH_LIB_PATH])
 
     if device_type == "cuda" and IS_HIP_EXTENSION:
-        lib_dir = 'lib'
+        lib_dir = '%LIB_DIR%'
         paths.append(_join_rocm_home(lib_dir))
         if HIP_HOME is not None:
-            paths.append(os.path.join(HIP_HOME, 'lib'))
+            paths.append(os.path.join(HIP_HOME, '%LIB_DIR%'))
     elif device_type == "cuda":
         if cross_target_platform == "windows":
             lib_dir = os.path.join('lib', 'x64')