Include link options in .pc generation

Author: vector-of-bool

src/libmongoc/src/libmongoc.pc.in

@@ -27,7 +27,11 @@ Libs: -L${libdir} -l$<TARGET_PROPERTY:OUTPUT_NAME> ~@space@~
     %define libs_prop $<TARGET_PROPERTY:pc_LIBS>
     #~ Remove duplicate items, which will usually be redundant link paths:
     %define libs $<REMOVE_DUPLICATES:libs_prop>
-    $<JOIN:libs,@space@>
+    $<JOIN:libs,@space@>~
+
+    #~ Add link options. Don't remove duplicates, because they may be important
+    %define link_opts $<TARGET_PROPERTY:INTERFACE_LINK_OPTIONS>
+    $<$<<not-empty:link_opts>>:@space@$<JOIN:link_opts,@space@>>
 
 ~@newline@~