8212701: remove sun.desktop property from launcher code

Reviewed-by: serb, alanb, rriggs

src/java.base/share/native/libjava/System.c

@@ -221,11 +221,6 @@ Java_jdk_internal_util_SystemProps_00024Raw_platformProperties(JNIEnv *env, jcla
      */
     PUTPROP(propArray, _java_awt_graphicsenv_NDX, sprops->graphics_env);
 
-    /*
-     * The sun.desktop property is currently only set for Gnome and Windows desktops.
-     */
-    PUTPROP(propArray, _sun_desktop_NDX, sprops->desktop);
-
     PUTPROP_PlatformString(propArray, _java_io_tmpdir_NDX, sprops->tmp_dir);
 
     PUTPROP_PlatformString(propArray, _user_name_NDX, sprops->user_name);

src/java.base/share/native/libjava/java_props.h

@@ -82,8 +82,6 @@ typedef struct {
 
     char *patch_level;          /* patches/service packs installed */
 
-    char *desktop;              /* Desktop name. */
-
 #ifdef MACOSX
     // These are for proxy-related information.
     // Note that if these platform-specific extensions get out of hand we should make a new