Allow building kati & makeparallel with soong

This uses far fewer hacks in order to build these host tools, but will
require more libraries(libc++,etc) from unbundled and stripped down
branches.

Once this becomes the only option, all builds will happen after soong
runs. Then the toolchain / global cflags information will be able to be
moved from make to soong (and exported back to make).

Change-Id: I270b1d92bcef28a96fbc3ec9910d9bd0c101ac0f
diff --git a/core/soong.mk b/core/soong.mk
index aab26de..646c68e 100644
--- a/core/soong.mk
+++ b/core/soong.mk
@@ -4,6 +4,9 @@
 SOONG_ANDROID_MK := $(SOONG_OUT_DIR)/Android.mk
 SOONG_VARIABLES := $(SOONG_OUT_DIR)/soong.variables
 SOONG_IN_MAKE := $(SOONG_OUT_DIR)/.soong.in_make
+SOONG_HOST_EXECUTABLES := $(SOONG_OUT_DIR)/host/$(HOST_PREBUILT_TAG)/bin
+KATI := $(SOONG_HOST_EXECUTABLES)/ckati
+MAKEPARALLEL := $(SOONG_HOST_EXECUTABLES)/makeparallel
 
 ifeq (,$(filter /%,$(SOONG_OUT_DIR)))
 SOONG_TOP_RELPATH := $(shell python -c "import os; print os.path.relpath('$(TOP)', '$(SOONG_OUT_DIR)')")
@@ -57,4 +60,7 @@
 
 # Build an Android.mk listing all soong outputs as prebuilts
 $(SOONG_ANDROID_MK): $(SOONG) $(SOONG_VARIABLES) $(SOONG_IN_MAKE) FORCE
-	$(hide) $(SOONG) $(SOONG_BUILD_NINJA) $(NINJA_ARGS)
+	$(hide) $(SOONG) $(KATI) $(MAKEPARALLEL) $(NINJA_ARGS)
+
+$(KATI): $(SOONG_ANDROID_MK)
+$(MAKEPARALLEL): $(SOONG_ANDROID_MK)