Fix integration of pass plugins with llvm dylib

Call llvm_process_pass_plugin from clang when in standalone mode.

Differential Revision: https://reviews.llvm.org/D74464

GitOrigin-RevId: d21664cce1db8debe2528f36b1fbd2b8af9c9401
diff --git a/CMakeLists.txt b/CMakeLists.txt
index 781c3eb..dc1413f 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -864,6 +864,7 @@
 
 if(CLANG_BUILT_STANDALONE)
   llvm_distribution_add_targets()
+  process_llvm_pass_plugins()
 endif()
 
 configure_file(