* Makefile.in (ggc-common.o): Update.
	* c-decl.c (lang_mark_tree): Rename c_mark_tree.
	* c-lang.c (LANG_HOOKS_MARK_TREE): Redefine.
	* c-tree.h (c_mark_tree): New.
	* ggc-common.c: Include langhooks.h.
	(gcc_mark_trees): Use new langhook.
	* ggc-callbacks.c: Delete file.
	* ggc.h (lang_mark_tree): Remove.
	* langhooks-def.h (LANG_HOOKS_MARK_TREE): New.
	(LANG_HOOKS_INITIALIZER): Update.
	* langhooks.h (struct lang_hooks): New hook.
ada:
	* misc.c (LANG_HOOKS_MARK_TREE): Redefine.
	(lang_mark_tree): Make static, rename.
cp:
	* cp-lang.c (LANG_HOOKS_MARK_TREE): Redefine.
	* cp-tree.h (cxx_mark_tree): New.
	* decl.c (lang_mark_tree): Rename cxx_mark_tree.
f:
	* com.c (LANG_HOOKS_MARK_TREE): Redefine.
	(lang_mark_tree): Rename ffe_mark_tree, make static.
java:
	* decl.c (lang_mark_tree): Rename java_mark_tree.
	* java-tree.h (java_mark_tree): New.
	* java-lang.c (LANG_HOOKS_MARK_TREE): Redefine.
objc:
	* objc-lang.c (LANG_HOOKS_MARK_TREE): Redefine.

From-SVN: r51369