[runtimes] Make sure LLVM_LIT_ARGS is set before including individual runtimes

Otherwise, the individual `check-cxx`, `check-cxxabi` and similar targets
will not know about `LLVM_LIT_ARGS`, and we'll end up running lit without
any argument.

Differential Revision: https://reviews.llvm.org/D112035

Author: ldionne

runtimes/CMakeLists.txt

@@ -152,6 +152,14 @@ foreach(entry ${runtimes})
   set(HAVE_${canon_name} ON)
 endforeach()
 
+if(LLVM_INCLUDE_TESTS)
+  set(LIT_ARGS_DEFAULT "-sv --show-xfail --show-unsupported")
+  if (MSVC OR XCODE)
+    set(LIT_ARGS_DEFAULT "${LIT_ARGS_DEFAULT} --no-progress-bar")
+  endif()
+  set(LLVM_LIT_ARGS "${LIT_ARGS_DEFAULT}" CACHE STRING "Default options for lit")
+endif()
+
 # We do this in two loops so that HAVE_* is set for each runtime before the
 # other runtimes are added.
 foreach(entry ${runtimes})
@@ -179,13 +187,6 @@ endforeach()
 if(LLVM_INCLUDE_TESTS)
   # Add a global check rule now that all subdirectories have been traversed
   # and we know the total set of lit testsuites.
-
-  set(LIT_ARGS_DEFAULT "-sv --show-xfail --show-unsupported")
-  if (MSVC OR XCODE)
-    set(LIT_ARGS_DEFAULT "${LIT_ARGS_DEFAULT} --no-progress-bar")
-  endif()
-  set(LLVM_LIT_ARGS "${LIT_ARGS_DEFAULT}" CACHE STRING "Default options for lit")
-
   add_lit_target(check-runtimes
     "Running all regression tests"
     ${RUNTIMES_LIT_TESTSUITES}