Revert "[libclc] Change symlinks to copies on Windows (llvm#147759)"

This reverts commit 9b5959d.

Author: mgorny

libclc/cmake/modules/AddLibclc.cmake

@@ -425,17 +425,11 @@ function(add_libclc_builtin_set)
       WORKING_DIRECTORY ${CMAKE_CURRENT_SOURCE_DIR} )
   endif()
 
-  if(CMAKE_HOST_UNIX OR LLVM_USE_SYMLINKS)
-    set(LIBCLC_LINK_OR_COPY create_symlink)
-  else()
-    set(LIBCLC_LINK_OR_COPY copy)
-  endif()
-
-  foreach( a IN LISTS ARG_ALIASES )
+  foreach( a ${ARG_ALIASES} )
     set( alias_suffix "${a}-${ARG_TRIPLE}.bc" )
     add_custom_command(
       OUTPUT ${LIBCLC_OUTPUT_LIBRARY_DIR}/${alias_suffix}
-      COMMAND ${CMAKE_COMMAND} -E ${LIBCLC_LINK_OR_COPY} ${libclc_builtins_lib} ${LIBCLC_OUTPUT_LIBRARY_DIR}/${alias_suffix}
+      COMMAND ${CMAKE_COMMAND} -E create_symlink ${libclc_builtins_lib} ${LIBCLC_OUTPUT_LIBRARY_DIR}/${alias_suffix}
       DEPENDS prepare-${obj_suffix}
     )
     add_custom_target( alias-${alias_suffix} ALL