[metacity] fix build with --disable-dependency-tracking

[Alberts Muktupāvels <muktupavels src gnome org>]

commit 632670273cc880917e78a152a3ae39e209b57864
Author: Zoltán Böszörményi <zboszor gmail com>
Date:   Sat Aug 28 05:58:25 2021 +0200

    fix build with --disable-dependency-tracking
    
    With split build and source directories AND --disable-dependency-tracking
    (like the way Yocto builds are done) there's a reproducible make
    failure on my Fedora 33 build host:
    
    | Making all in src
    | make[2]: Entering directory '.../metacity/1_3.40.0-r0/build/src'
    | .../metacity/1_3.40.0-r0/recipe-sysroot-native/usr/bin/glib-mkenums --template 
../../metacity-3.40.0/src/core/meta-enum-types.c.in ../../metacity-3.40.0/src/core/window-private.h 
../../metacity-3.40.0/src/include/meta-compositor.h  > \
    |       meta-enum-types.c.tmp && mv meta-enum-types.c.tmp core/meta-enum-types.c
    | .../metacity/1_3.40.0-r0/recipe-sysroot-native/usr/bin/glib-mkenums --template 
../../metacity-3.40.0/src/core/meta-enum-types.h.in ../../metacity-3.40.0/src/core/window-private.h 
../../metacity-3.40.0/src/include/meta-compositor.h  > \
    |       meta-enum-types.h.tmp && mv meta-enum-types.h.tmp core/meta-enum-types.h
    | mv: cannot move 'meta-enum-types.c.tmp' to 'core/meta-enum-types.c'mv: cannot move 
'meta-enum-types.h.tmp' to 'core/meta-enum-types.h': No such file or directory
    | : No such file or directory
    | make[2]: *** [Makefile:2240: core/meta-enum-types.c] Error 1
    
    https://gitlab.gnome.org/GNOME/metacity/-/merge_requests/24
    
    Signed-off-by: Zoltán Böszörményi <zboszor gmail com>

 configure.ac    | 1 +
 src/Makefile.am | 2 ++
 2 files changed, 3 insertions(+)
---
diff --git a/configure.ac b/configure.ac
index ebb00b85..04aafb94 100644
--- a/configure.ac
+++ b/configure.ac
@@ -139,6 +139,7 @@ dnl **************************************************************************
 AC_SUBST(ACLOCAL_AMFLAGS, "\${ACLOCAL_FLAGS}")
 
 AC_PROG_CC
+AC_PROG_MKDIR_P
 AC_ISC_POSIX
 AC_HEADER_STDC
 
diff --git a/src/Makefile.am b/src/Makefile.am
index f86af600..4aa3fdae 100644
--- a/src/Makefile.am
+++ b/src/Makefile.am
@@ -204,10 +204,12 @@ ENUM_TYPES = \
        $(NULL)
 
 core/meta-enum-types.c: core/meta-enum-types.c.in $(ENUM_TYPES) Makefile.am
+       $(MKDIR_P) core
        $(AM_V_GEN) $(GLIB_MKENUMS) --template $(srcdir)/core/meta-enum-types.c.in $(ENUM_TYPES) > \
                meta-enum-types.c.tmp && mv meta-enum-types.c.tmp core/meta-enum-types.c
 
 core/meta-enum-types.h: core/meta-enum-types.h.in $(ENUM_TYPES) Makefile.am
+       $(MKDIR_P) core
        $(AM_V_GEN) $(GLIB_MKENUMS) --template $(srcdir)/core/meta-enum-types.h.in $(ENUM_TYPES) > \
                meta-enum-types.h.tmp && mv meta-enum-types.h.tmp core/meta-enum-types.h