[cmake] [libunwind] Call llvm_setup_rpath() when adding shared libraries.

Clang and llvm already use llvm_setup_rpath(), so this change will
help standarize rpath usage across all projects.

Differential Revision: https://reviews.llvm.org/D42461

git-svn-id: https://llvm.org/svn/llvm-project/libunwind/trunk@323496 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/src/CMakeLists.txt b/src/CMakeLists.txt
index 2d2ec13..601c258 100644
--- a/src/CMakeLists.txt
+++ b/src/CMakeLists.txt
@@ -108,6 +108,9 @@
 # Build the shared library.
 if (LIBUNWIND_ENABLE_SHARED)
   add_library(unwind_shared SHARED $<TARGET_OBJECTS:unwind_objects>)
+  if(LLVM_FOUND)
+    llvm_setup_rpath(unwind_shared)
+  endif()
   target_link_libraries(unwind_shared ${libraries})
   set_target_properties(unwind_shared
                         PROPERTIES