Don't compile gimpmarshal source file many times

Also, removes gimpmarshal.h from a source file that didn't need it.

app/display/meson.build

@@ -107,7 +107,7 @@ libappdisplay_sources = [
   appdisplayenums,
   gitversion_h,
 
-  appcoremarshal,
+  appcoremarshal[1],
 ]
 
 libappdisplay = static_library('appdisplay',

app/gegl/gimptilehandlervalidate.c

@@ -26,7 +26,6 @@
 #include "gimp-gegl-types.h"
 
 #include "core/gimpchunkiterator.h"
-#include "core/gimpmarshal.h"
 
 #include "gimp-gegl-loops.h"
 #include "gimp-gegl-utils.h"

app/paint/meson.build

@@ -54,7 +54,7 @@ libapppaint_sources = [
   'gimpsourceoptions.c',
   apppaintenums,
 
-  appcoremarshal,
+  appcoremarshal[1],
 ]
 
 libapppaint = static_library('apppaint',

app/pdb/meson.build

@@ -62,7 +62,7 @@ libappinternalprocs_sources = [
   'unit-cmds.c',
   'vectors-cmds.c',
 
-  appcoremarshal,
+  appcoremarshal[1],
 ]
 
 libapppdb = static_library('apppdb',

app/plug-in/meson.build

@@ -46,7 +46,7 @@ libappplugin_sources = [
   'plug-in-rc.c',
   apppluginenums,
 
-  appcoremarshal,
+  appcoremarshal[1],
 ]
 
 libappplugin = static_library('appplug-in',

app/tools/meson.build

@@ -130,7 +130,7 @@ libapptools_sources = [
   'tool_manager.c',
   apptoolsenums,
 
-  appcoremarshal,
+  appcoremarshal[1],
 ]
 
 libapptools = static_library('apptools',

app/vectors/meson.build

@@ -13,7 +13,7 @@ libappvectors_sources = [
   'gimpvectorspropundo.c',
   'gimpvectorsundo.c',
 
-  appcoremarshal,
+  appcoremarshal[1],
 ]
 
 libappvectors = static_library('appvectors',

app/widgets/meson.build

@@ -236,7 +236,7 @@ libappwidgets_sources = [
   'gimpwindowstrategy.c',
   appwidgetsenums,
 
-  appcoremarshal,
+  appcoremarshal[1],
 ]