Do not apply offload-compile options without runtime

Author: Meinersbur

flang/unittests/CMakeLists.txt

@@ -11,6 +11,11 @@ add_custom_target(FlangUnitTests)
 set_target_properties(FlangUnitTests PROPERTIES FOLDER "Flang/Tests")
 
 function(add_flang_unittest_offload_properties target)
+  # Do not apply runtime properties if not even compiling the runtime.
+  if (NOT FLANG_INCLUDE_RUNTIME)
+    return ()
+  endif ()
+
   # Set CUDA_RESOLVE_DEVICE_SYMBOLS.
   if (FLANG_EXPERIMENTAL_CUDA_RUNTIME)
     set_target_properties(${target}