Separate aidl dependencies from compiler dependencies

Both aidl and clang/gcc were putting their dependencies in the same
place.  Move aidl's dependencies to a file ending with .aidl.P rather
than the compiler's .P.

While here, inform kati that we have these special dep files.

Bug:26409006
Test: Rebuild, note both files being generated

Change-Id: I29d2eea822235d60713c2059f3a314e475eb5aa3

core/binary.mk

@@ -741,7 +741,13 @@ aidl_gen_include_root := $(intermediates)/aidl-generated/include
 # Thus we'll actually generate source for each architecture.
 $(foreach s,$(aidl_src),\
     $(eval $(call define-aidl-cpp-rule,$(s),$(aidl_gen_cpp_root),aidl_gen_cpp)))
--include $(addsuffix .P,$(basename $(aidl_gen_cpp)))
+ifeq ($(BUILDING_WITH_NINJA),true)
+$(foreach cpp,$(aidl_gen_cpp), \
+    $(eval $(cpp) : .KATI_DEPFILE := $(addsuffix .aidl.P,$(basename $(cpp)))))
+else
+  -include $(addsuffix .aidl.P,$(basename $(aidl_gen_cpp)))
+endif
+
 
 $(aidl_gen_cpp) : PRIVATE_MODULE := $(LOCAL_MODULE)
 $(aidl_gen_cpp) : PRIVATE_HEADER_OUTPUT_DIR := $(aidl_gen_include_root)

core/definitions.mk

@@ -989,7 +989,7 @@ define transform-aidl-to-cpp
 @mkdir -p $(dir $@)
 @mkdir -p $(PRIVATE_HEADER_OUTPUT_DIR)
 @echo "Generating C++ from AIDL: $(PRIVATE_MODULE) <= $<"
-$(hide) $(AIDL_CPP) -d$(basename $@).P $(PRIVATE_AIDL_FLAGS) \
+$(hide) $(AIDL_CPP) -d$(basename $@).aidl.P $(PRIVATE_AIDL_FLAGS) \
     $< $(PRIVATE_HEADER_OUTPUT_DIR) $@
 endef