When building shared libraries, link to required system libraries.

PR 8375

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@116479 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/cmake/modules/AddLLVM.cmake b/cmake/modules/AddLLVM.cmake
index 22a456e..b7ebe19 100755
--- a/cmake/modules/AddLLVM.cmake
+++ b/cmake/modules/AddLLVM.cmake
@@ -9,6 +9,12 @@
   if( LLVM_COMMON_DEPENDS )
     add_dependencies( ${name} ${LLVM_COMMON_DEPENDS} )
   endif( LLVM_COMMON_DEPENDS )
+
+  if( BUILD_SHARED_LIBS )
+    get_system_libs(sl)
+    target_link_libraries( ${name} ${sl} )
+  endif()
+
   install(TARGETS ${name}
     LIBRARY DESTINATION lib${LLVM_LIBDIR_SUFFIX}
     ARCHIVE DESTINATION lib${LLVM_LIBDIR_SUFFIX})