Clean up Android.mk.

Export our includes, and use exported includes.
Also drop the symlink to cxxabi.h since we can get that from libc++abi
without pulling in the unwind headers now.

Change-Id: I2f9a5f7bdad6613433022f4e3888ef9336c8ebfb
diff --git a/Android.mk b/Android.mk
index 5ce2a84..e4a42a2 100644
--- a/Android.mk
+++ b/Android.mk
@@ -46,7 +46,6 @@
 
 LIBCXX_C_INCLUDES := \
 	$(LOCAL_PATH)/include/ \
-	external/libcxxabi/include \
 
 LIBCXX_CPPFLAGS := \
 	-std=c++14 \
@@ -59,6 +58,7 @@
 LOCAL_CLANG := true
 LOCAL_SRC_FILES := $(LIBCXX_SRC_FILES)
 LOCAL_C_INCLUDES := $(LIBCXX_C_INCLUDES)
+LOCAL_EXPORT_C_INCLUDE_DIRS := $(LOCAL_PATH)/include
 LOCAL_CPPFLAGS := $(LIBCXX_CPPFLAGS)
 LOCAL_RTTI_FLAG := -frtti
 LOCAL_WHOLE_STATIC_LIBRARIES := libc++abi
@@ -69,6 +69,7 @@
 include $(CLEAR_VARS)
 LOCAL_MODULE := libc++
 LOCAL_CLANG := true
+LOCAL_EXPORT_C_INCLUDE_DIRS := $(LOCAL_PATH)/include external/libcxxabi/include
 LOCAL_WHOLE_STATIC_LIBRARIES := libc++_static
 LOCAL_SHARED_LIBRARIES := libdl
 LOCAL_CXX_STL := none
@@ -82,6 +83,7 @@
 LOCAL_CLANG := true
 LOCAL_SRC_FILES := $(LIBCXX_SRC_FILES)
 LOCAL_C_INCLUDES := $(LIBCXX_C_INCLUDES)
+LOCAL_EXPORT_C_INCLUDE_DIRS := $(LOCAL_PATH)/include
 LOCAL_CPPFLAGS := $(LIBCXX_CPPFLAGS)
 LOCAL_RTTI_FLAG := -frtti
 LOCAL_WHOLE_STATIC_LIBRARIES := libc++abi
@@ -96,6 +98,7 @@
 include $(CLEAR_VARS)
 LOCAL_MODULE := libc++
 LOCAL_CLANG := true
+LOCAL_EXPORT_C_INCLUDE_DIRS := $(LOCAL_PATH)/include external/libcxxabi/include
 LOCAL_LDFLAGS := -nodefaultlibs
 LOCAL_WHOLE_STATIC_LIBRARIES := libc++_static
 LOCAL_MULTILIB := both
diff --git a/include/cxxabi.h b/include/cxxabi.h
deleted file mode 120000
index 15d74d2..0000000
--- a/include/cxxabi.h
+++ /dev/null
@@ -1 +0,0 @@
-../../libcxxabi/include/cxxabi.h
\ No newline at end of file