* expression.h (BINOP_CONCAT): Document use for self concatenation

	* expression.h (BINOP_CONCAT): Document use for self concatenation
	an integral number of times.
	* language.c (binop_type_check):  Extend BINOP_CONCAT for self
	concatenation case.
	* valarith.c (value_concat):  Rewrite to support self
	concatenation an integral number of times.
	**** start-sanitize-chill ****
	* Makefile.in (ch-exp.tab.c):  Change "expect" message.
	* ch-exp.y (FIXME's):  Make all FIXME tokens distinct, to
	eliminate hundreds of spurious shift/reduce and reduce/reduce
	conflicts that mask the 5 real ones.
	* ch-exp.y (STRING, CONSTANT, SC):  Remove unused tokens.
	* ch-exp.y (integer_literal_expression):  Remove production,
	no longer used.
	**** end-sanitize-chill ****