Use LLVM's new DESTDIR-less PROJ_* variables.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@97744 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/docs/Makefile b/docs/Makefile
index 9b706c7..e9bbb28 100644
--- a/docs/Makefile
+++ b/docs/Makefile
@@ -48,11 +48,11 @@
 
 install-html: $(PROJ_OBJ_DIR)/html.tar.gz
 	$(Echo) Installing HTML documentation
-	$(Verb) $(MKDIR) $(PROJ_docsdir)/html
-	$(Verb) $(MKDIR) $(PROJ_docsdir)/html/img
-	$(Verb) $(DataInstall) $(HTML) $(PROJ_docsdir)/html
-#	$(Verb) $(DataInstall) $(IMAGES) $(PROJ_docsdir)/html/img
-	$(Verb) $(DataInstall) $(PROJ_OBJ_DIR)/html.tar.gz $(PROJ_docsdir)
+	$(Verb) $(MKDIR) $(DESTDIR)$(PROJ_docsdir)/html
+	$(Verb) $(MKDIR) $(DESTDIR)$(PROJ_docsdir)/html/img
+	$(Verb) $(DataInstall) $(HTML) $(DESTDIR)$(PROJ_docsdir)/html
+#	$(Verb) $(DataInstall) $(IMAGES) $(DESTDIR)$(PROJ_docsdir)/html/img
+	$(Verb) $(DataInstall) $(PROJ_OBJ_DIR)/html.tar.gz $(DESTDIR)$(PROJ_docsdir)
 
 $(PROJ_OBJ_DIR)/html.tar.gz: $(HTML)
 	$(Echo) Packaging HTML documentation
@@ -63,11 +63,11 @@
 
 install-doxygen: doxygen
 	$(Echo) Installing doxygen documentation
-	$(Verb) $(MKDIR) $(PROJ_docsdir)/html/doxygen
-	$(Verb) $(DataInstall) $(PROJ_OBJ_DIR)/doxygen.tar.gz $(PROJ_docsdir)
+	$(Verb) $(MKDIR) $(DESTDIR)$(PROJ_docsdir)/html/doxygen
+	$(Verb) $(DataInstall) $(PROJ_OBJ_DIR)/doxygen.tar.gz $(DESTDIR)$(PROJ_docsdir)
 	$(Verb) cd $(PROJ_OBJ_DIR)/doxygen && \
 	  $(FIND) . -type f -exec \
-	    $(DataInstall) {} $(PROJ_docsdir)/html/doxygen \;
+	    $(DataInstall) {} $(DESTDIR)$(PROJ_docsdir)/html/doxygen \;
 
 doxygen: regendoc $(PROJ_OBJ_DIR)/doxygen.tar.gz
 
@@ -94,4 +94,4 @@
 
 uninstall-local::
 	$(Echo) Uninstalling Documentation
-	$(Verb) $(RM) -rf $(PROJ_docsdir)
+	$(Verb) $(RM) -rf $(DESTDIR)$(PROJ_docsdir)