patch 9.2.0013: parallel make invocation may break Wayland header generation

Problem:  parallel make invocation may break Wayland header generation
Solution: Use single make target to generate Wayland protocol files.
          (Jan Palus)

$(WAYLAND_SRC) contains up to 4 files which, given right timing and
parallelization level, can spawn 4 independent `make` processes during
parallel build. Each process generates same set of files intermittently
leading to inconsistent results. Instead use one common target each
source file depends on.

fixes:  #19419
closes: #19420

Signed-off-by: Jan Palus <jpalus@fastmail.com>
Signed-off-by: Christian Brabandt <cb@256bit.org>

src/Makefile

@@ -1607,7 +1607,10 @@ EXTRA_SRC = if_lua.c if_mzsch.c auto/if_perl.c \
 	    gui_beval.c netbeans.c job.c channel.c \
 	    $(GRESOURCE_SRC)
 
-$(WAYLAND_SRC):
+$(WAYLAND_SRC): genwaylandproto
+
+.PHONY: genwaylandproto
+genwaylandproto:
 	cd auto/wayland; $(MAKE)
 
 # Needed for parallel jobs to work

src/version.c

@@ -734,6 +734,8 @@ static char *(features[]) =
 
 static int included_patches[] =
 {   /* Add new patch number below this line */
+/**/
+    13,
 /**/
     12,
 /**/