Reorder builds based by ordering.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@184794 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/tools/Makefile b/tools/Makefile
index b33c74d..c8bc583 100644
--- a/tools/Makefile
+++ b/tools/Makefile
@@ -11,14 +11,14 @@
 
 include $(CLANG_LEVEL)/../../Makefile.config
 
-DIRS := driver libclang c-index-test arcmt-test c-arcmt-test diagtool \
-        clang-check clang-format
+DIRS := libclang c-index-test arcmt-test c-arcmt-test
+PARALLEL_DIRS := driver diagtool clang-check clang-format
 
 # Recurse into the extra repository of tools if present.
-OPTIONAL_DIRS := extra
+OPTIONAL_PARALLEL_DIRS := extra
 
 ifeq ($(BUILD_CLANG_ONLY),YES)
-  DIRS := driver libclang c-index-test
+  PARALLEL_DIRS := driver libclang c-index-test
   OPTIONAL_DIRS :=
 endif