Let make track the autoload_runtime

In the commit before this was mentioned as better solution and it
required less work than expected. We now track the file and create it as
the normal user and because it exists we don't recreate it in the
install-domserver step as root (assuming it runs with `sudo`). It will
still create it if it doesn't exist as domserver is a dependency for
install-domserver (and in that case `composer` would run as root again,
so prompting the user to accept this risk).

I did not check if we can do the same for the development dependencies
or what this means for the `inplace` targets.

Makefile

@@ -44,7 +44,7 @@ dist: distdocs
 endif
 
 # MAIN TARGETS
-domserver: domserver-configure paths.mk config composer-dump-autoload
+domserver: domserver-configure paths.mk config
 judgehost: judgehost-configure paths.mk config
 docs: paths.mk config
 install-domserver: domserver domserver-create-dirs
@@ -76,14 +76,6 @@ endif
 composer-dependencies-dev:
 	composer $(subst 1,-q,$(QUIET)) install --prefer-dist --no-scripts --no-plugins
 
-# Dump autoload dependencies (including plugins)
-# This is needed since symfony/runtime is a Composer plugin that runs while dumping
-# the autoload file
-composer-dump-autoload:
-ifeq (,$(wildcard ./lib/vendor/autoload_runtime.php))
-	composer $(subst 1,-q,$(QUIET)) dump-autoload -o -a
-endif
-
 composer-dump-autoload-dev:
 	composer $(subst 1,-q,$(QUIET)) dump-autoload
 
@@ -103,7 +95,7 @@ build-scripts:
 
 # List of SUBDIRS for recursive targets:
 build:             SUBDIRS=        lib           misc-tools
-domserver:         SUBDIRS=etc         sql       misc-tools webapp
+domserver:         SUBDIRS=etc     lib sql       misc-tools webapp
 install-domserver: SUBDIRS=etc     lib sql       misc-tools webapp example_problems
 judgehost:         SUBDIRS=etc             judge misc-tools
 install-judgehost: SUBDIRS=etc     lib     judge misc-tools

lib/Makefile

@@ -1,6 +1,9 @@
 ifndef TOPDIR
 TOPDIR=..
 endif
+
+REC_TARGETS = domserver
+
 include $(TOPDIR)/Makefile.global
 
 OBJECTS = $(addsuffix $(OBJEXT),lib.error lib.misc)
@@ -31,3 +34,5 @@ install-domserver:
 install-judgehost:
 	$(INSTALL_DATA) -t $(DESTDIR)$(judgehost_libdir)    *.php *.sh
 	$(INSTALL_PROG) -t $(DESTDIR)$(judgehost_libdir)    alert
+
+domserver:         SUBDIRS=vendor

lib/vendor/Makefile

@@ -0,0 +1,12 @@
+ifndef TOPDIR
+TOPDIR=../..
+endif
+include $(TOPDIR)/Makefile.global
+
+clean-l:
+	rm -f autoload_runtime.php
+
+autoload_runtime.php:
+	composer $(subst 1,-q,$(QUIET)) dump-autoload -o -a -d $(TOPDIR)
+
+domserver: autoload_runtime.php