Move tools compiled by Soong to HOST_OUT_EXECUTABLES

Soong now installs native tools to HOST_OUT_EXECUTABLES instead
of SOONG_HOST_OUT_EXECUTABLES.

Also add a cleanspec for SOONG_HOST_OUT to remove old files from
SOONG_HOST_OUT_EXECUTABLES.

Bug: 204136549
Test: m checkbuild
Change-Id: Id18213b9294b6d2cf78f657740c6d5a02733b8ad
diff --git a/CleanSpec.mk b/CleanSpec.mk
index 639c4ef..fff49b3 100644
--- a/CleanSpec.mk
+++ b/CleanSpec.mk
@@ -760,6 +760,9 @@
 # Common R directory has been removed.
 $(call add-clean-step, rm -rf $(OUT_DIR)/target/common/R)
 
+# Most of SOONG_HOST_OUT_EXECUTABLES has been moved to HOST_OUT_EXECUTABLES
+$(call add-clean-step, rm -rf $(SOONG_HOST_OUT))
+
 # ************************************************
 # NEWER CLEAN STEPS MUST BE AT THE END OF THE LIST
 # ************************************************