Adding check for xargs. It is used in some non-default build rules and we need it to properly clean up after our Makefile creation when using some shells.

Bug 37095 r=mkaply@us.ibm.com r=jdunn@netscape.com

config/autoconf.mk.in

@@ -190,6 +190,7 @@ RANLIB		= @RANLIB@
 WHOAMI		= @WHOAMI@
 UNZIP_PROG	= @UNZIP@
 ZIP_PROG	= @ZIP@
+XARGS		= @XARGS@
 
 ifdef MOZ_NATIVE_JPEG
 JPEG_CFLAGS	= @JPEG_CFLAGS@

config/rules.mk

@@ -560,11 +560,11 @@ clean clobber realclean clobber_all:: $(SUBMAKEFILES)
 distclean:: $(SUBMAKEFILES)
 	+$(LOOP_OVER_DIRS)
 	rm -f $(ALL_TRASH) ; \
-	rm -rf $(ALL_TRASH_DIRS) \
+	rm -rf $(ALL_TRASH_DIRS) ;
-	$(wildcard *.map) \
+	echo $(wildcard *.map) \
 	Makefile .HSancillary $(DIST_GARBAGE) \
 	$(wildcard *.$(OBJ_SUFFIX)) $(wildcard *.ho) \
-	$(wildcard *.$(LIB_SUFFIX)) $(wildcard *$(DLL_SUFFIX))
+	$(wildcard *.$(LIB_SUFFIX)) $(wildcard *$(DLL_SUFFIX)) | $(XARGS) rm -f
 
 alltags:
 	rm -f TAGS

configure.in

@@ -313,6 +313,10 @@ if test -z "$ZIP" || test "$ZIP" = ":"; then
     MOZ_DISABLE_JAR_PACKAGING=1
 fi
 AC_PATH_PROG(SYSTEM_MAKEDEPEND, makedepend)
+AC_PATH_PROG(XARGS, xargs)
+if test -z "$XARGS" || test "$XARGS" = ":"; then
+    AC_MSG_ERROR([xargs not found in \$PATH .])
+fi
 
 dnl Be sure the make we use is GNU make.
 AC_PATH_PROGS(MAKE, gmake make, :)