Use libcxx makefile's do-installhdrs target. <rdar://problem/10397739>

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@145168 91177308-0d34-0410-b5e6-96231b3b80d8

runtime/libcxx/Makefile

@@ -15,7 +15,7 @@
 CLANG_LEVEL := ../..
 include $(CLANG_LEVEL)/Makefile
 
-PROJ_libcxx_hdrs := $(DESTDIR)$(PROJ_prefix)/lib/c++/v1
+PROJ_libcxx_hdrs := $(DESTDIR)$(PROJ_prefix)/lib
 
 # Expect libcxx to be in llvm/projects/libcxx
 LIBCXX_SRC_ROOT := $(LLVM_SRC_ROOT)/projects/libcxx
@@ -24,12 +24,8 @@ ifneq ($(CLANG_NO_RUNTIME),1)
 ifeq ($(shell test -d $(LIBCXX_SRC_ROOT) && echo OK),OK)
 
 install-local::
-	mkdir -p $(PROJ_libcxx_hdrs)/ext
-	rsync -r --exclude=".*" $(LIBCXX_SRC_ROOT)/include/* $(PROJ_libcxx_hdrs)
-	chmod 755 $(PROJ_libcxx_hdrs)
-	chmod 644 $(PROJ_libcxx_hdrs)/*
-	chmod 755 $(PROJ_libcxx_hdrs)/ext
-	chmod 644 $(PROJ_libcxx_hdrs)/ext/*
+	$(MAKE) -C $(LIBCXX_SRC_ROOT) \
+	  HEADER_DIR=$(PROJ_libcxx_hdrs) do-installhdrs
 
 endif
 endif