Remove duplication in binary dist rules

Rather than building complex sh stuff and echoing what we're doing
ourselves, use make rules to do the looping and let make print things
out.

Makefile

@@ -241,40 +241,31 @@ ifeq "$(darwin_TARGET_OS)" "1"
 BIN_DIST_TOP+=mk/fix_install_names.sh
 endif
 
-.PHONY: binary-dist-pre binary-dist binary-pack
+.PHONY: binary-dist-pre% binary-dist binary-pack
 
-binary-dist:: binary-dist-pre
+BINARY_DIST_PRE_RULES=$(foreach d,$(BinDistDirs),binary-dist-pre-$d)
+
+binary-dist:: binary-dist-pre $(BINARY_DIST_PRE_RULES)
 
 binary-dist-pre::
 ifeq "$(BIN_DIST)" ""
-	@echo "WARNING: To run the binary-dist target, you need to set BIN_DIST=1 in mk/build.mk" && exit 1
+	@echo "WARNING: To run the binary-dist target, you need to set BIN_DIST=1 in mk/build.mk"
+	@false
 endif
 	-rm -rf $(BIN_DIST_DIR)
 	-$(RM) $(BIN_DIST_DIR).tar.gz
-	@for i in $(BinDistDirs); do 		 	 \
-	  if test -d "$$i"; then 			 \
-	   echo $(MKDIRHIER) $(BIN_DIST_DIR)/bin/$(TARGETPLATFORM); \
-	   $(MKDIRHIER) $(BIN_DIST_DIR)/bin/$(TARGETPLATFORM); \
-	   echo $(MKDIRHIER) $(BIN_DIST_DIR)/lib/$(TARGETPLATFORM); \
-	   $(MKDIRHIER) $(BIN_DIST_DIR)/lib/$(TARGETPLATFORM); \
-	   echo $(MKDIRHIER) $(BIN_DIST_DIR)/share; \
-	   $(MKDIRHIER) $(BIN_DIST_DIR)/share; \
-	   echo $(MAKE) -C $$i $(MFLAGS) $(INSTALL_STAGE) install \
-		prefix=$(BIN_DIST_DIR) \
-		exec_prefix=$(BIN_DIST_DIR) \
-		bindir=$(BIN_DIST_DIR)/bin/$(TARGETPLATFORM) \
-		libdir=$(BIN_DIST_DIR)/lib/$(TARGETPLATFORM) \
-		libexecdir=$(BIN_DIST_DIR)/lib/$(TARGETPLATFORM) \
-		datadir=$(BIN_DIST_DIR)/share; \
-	   $(MAKE) -C $$i $(MFLAGS) $(INSTALL_STAGE) install \
-		prefix=$(BIN_DIST_DIR) \
-		exec_prefix=$(BIN_DIST_DIR) \
-		bindir=$(BIN_DIST_DIR)/bin/$(TARGETPLATFORM) \
-		libdir=$(BIN_DIST_DIR)/lib/$(TARGETPLATFORM) \
-		libexecdir=$(BIN_DIST_DIR)/lib/$(TARGETPLATFORM) \
-		datadir=$(BIN_DIST_DIR)/share; \
-	  fi; \
-	done
+	$(MKDIRHIER) $(BIN_DIST_DIR)/bin/$(TARGETPLATFORM)
+	$(MKDIRHIER) $(BIN_DIST_DIR)/lib/$(TARGETPLATFORM)
+	$(MKDIRHIER) $(BIN_DIST_DIR)/share
+
+$(BINARY_DIST_PRE_RULES): binary-dist-pre-%:
+	$(MAKE) -C $* $(MFLAGS) $(INSTALL_STAGE) install \
+	        prefix=$(BIN_DIST_DIR) \
+	        exec_prefix=$(BIN_DIST_DIR) \
+	        bindir=$(BIN_DIST_DIR)/bin/$(TARGETPLATFORM) \
+	        libdir=$(BIN_DIST_DIR)/lib/$(TARGETPLATFORM) \
+	        libexecdir=$(BIN_DIST_DIR)/lib/$(TARGETPLATFORM) \
+	        datadir=$(BIN_DIST_DIR)/share
 
 binary-dist::
 	@for i in $(BIN_DIST_TOP); do \