Another const-ify patch

[Jeffrey A Law]

  > Mon Jan 18 21:39:46 1999  Kaveh R. Ghazi  <ghazi@caip.rutgers.edu>
  > 
  > 	* cpplib.h (progname): Qualify a char* with the keyword `const'.
  > 
  > 	* cppmain.c (progname): Likewise.
  > 
  > 	* final.c (bb_str): Likewise.
  > 	(add_bb_string, final_scan_insn, output_asm_insn): Likewise.
  > 
  > 	* fix-header.c (progname, read_scan_file): Likewise.
  > 
  > 	* gen-protos.c (progname): Likewise.
  > 
  > 	* genoutput.c (output_epilogue, process_template): Likewise.
  > 	
  > 	* local-alloc.c (requires_inout, block_alloc): Likewise.
  > 
  > 	* output.h (output_asm_insn, assemble_string): Likewise.
  > 
  > 	* recog.c (recog_constraints, check_asm_operands,
  > 	decode_asm_operands, extract_insn, preprocess_constraints,
  > 	constrain_operands): Likewise.
  > 
  > 	* recog.h (operand_alternative, recog_constraints, insn_template,
  > 	insn_outfun, insn_operand_constraint, insn_name): Likewise.
  > 
  > 	* regclass.c (record_reg_classes, scan_one_insn): Likewise.
  > 
  > 	* regmove.c (find_matches): Likewise.
  > 
  > 	* reload.c (alternative_allows_memconst): Likewise.
  > 
  > 	* reload1.c (constraint_accepts_reg_p,
  > 	reload_cse_simplify_operands): Likewise.
  > 
  > 	* rtl.h (decode_asm_operands): Likewise.
  > 
  > 	* scan.h (fn_decl): Likewise.
  > 
  > 	* varasm.c (assemble_string): Likewise.
Fine, except for the cpp stuff.  Zack asked folks to lay off that file for
a little while.  Zack & I need to talk a because I need to beat on that file
to get the merge checked in.  Until we figure out what we're doing with cpp*
let's not hack it up too much.

jeff