* symtab.h (SYMBOL_INIT_DEMANGLED_NAME): Initialize contents

	* symtab.h (SYMBOL_INIT_DEMANGLED_NAME):  Initialize contents
	of demangled name fields to NULL if no demangling exists for
	a symbol.  SYMBOL_INIT_LANGUAGE_SPECIFIC does this for new
	symbols if their language is known at the time they are created,
	but sometimes the language is not known until later.