* lex.c: Get WCHAR_TYPE_SIZE from wchar_type_node.
	* lang-specs.h: If -fshort-wchar, override __WCHAR_TYPE__.
	* decl2.c (lang_f_options): Add -fshort-wchar.
	* cp-tree.h: Declare flag_short_wchar.
	* decl.c (init_decl_processing): If -fshort-wchar, use 'short unsigned
	int' for wchar_t.

From-SVN: r29639