Fix assert handling for LLVM.

If we undefined NDEBUG first, the system-wide -DNDEBUG will override it, thus
causing asserts to still remain off.

Change-Id: I84342ca36595bbd7e310ea19c6907938fba4cee7
diff --git a/llvm-device-build.mk b/llvm-device-build.mk
index 156a39b..30baec0 100644
--- a/llvm-device-build.mk
+++ b/llvm-device-build.mk
@@ -27,9 +27,9 @@
 
 ifeq ($(LLVM_ENABLE_ASSERTION),true)
 LOCAL_CFLAGS :=	\
+	$(LOCAL_CFLAGS) \
 	-D_DEBUG	\
-	-UNDEBUG	\
-	$(LOCAL_CFLAGS)
+	-UNDEBUG
 endif
 
 ifneq ($(REQUIRES_EH),1)
diff --git a/llvm-host-build.mk b/llvm-host-build.mk
index 67c3808..9fd7435 100644
--- a/llvm-host-build.mk
+++ b/llvm-host-build.mk
@@ -13,9 +13,9 @@
 
 ifeq ($(LLVM_ENABLE_ASSERTION),true)
 LOCAL_CFLAGS :=	\
+	$(LOCAL_CFLAGS) \
 	-D_DEBUG	\
-	-UNDEBUG	\
-	$(LOCAL_CFLAGS)
+	-UNDEBUG
 endif
 
 ifneq ($(REQUIRES_EH),1)