Fix copyright dates.

From-SVN: r24530

gcc/Makefile.in

 # Makefile for GNU C compiler.
-#   Copyright (C) 1987, 88, 90-97, 1998 Free Software Foundation, Inc.
+#   Copyright (C) 1987, 88, 90-98, 1999 Free Software Foundation, Inc.
 
 #This file is part of GNU CC.
 

gcc/cccp.c

 /* C Compatible Compiler Preprocessor (CCCP)
-   Copyright (C) 1986, 87, 89, 92-97, 1998 Free Software Foundation, Inc.
+   Copyright (C) 1986, 87, 89, 92-98, 1999 Free Software Foundation, Inc.
    Written by Paul Rubin, June 1986
    Adapted to ANSI C, Richard Stallman, Jan 1987
 

gcc/cppfiles.c

 /* Part of CPP library.  (include file handling)
-   Copyright (C) 1986, 87, 89, 92 - 95, 1998 Free Software Foundation, Inc.
+   Copyright (C) 1986, 87, 89, 92 - 95, 98, 1999 Free Software Foundation, Inc.
    Written by Per Bothner, 1994.
    Based on CCCP program by Paul Rubin, June 1986
    Adapted to ANSI C, Richard Stallman, Jan 1987

gcc/cpplib.c

 /* CPP Library.
-   Copyright (C) 1986, 87, 89, 92-97, 1998 Free Software Foundation, Inc.
+   Copyright (C) 1986, 87, 89, 92-98, 1999 Free Software Foundation, Inc.
    Contributed by Per Bothner, 1994-95.
    Based on CCCP program by Paul Rubin, June 1986
    Adapted to ANSI C, Richard Stallman, Jan 1987

gcc/cpplib.h

 /* Definitions for CPP library.
-   Copyright (C) 1995, 1996, 1997 Free Software Foundation, Inc.
+   Copyright (C) 1995, 96-98, 1999 Free Software Foundation, Inc.
    Written by Per Bothner, 1994-95.
 
 This program is free software; you can redistribute it and/or modify it

gcc/gcc.c

 /* Compiler driver program that can handle many languages.
-   Copyright (C) 1987, 89, 92-97, 1998 Free Software Foundation, Inc.
+   Copyright (C) 1987, 89, 92-98, 1999 Free Software Foundation, Inc.
 
 This file is part of GNU CC.
 

gcc/prefix.c

 /* Utility to update paths from internal to external forms.
-   Copyright (C) 1997, 1998 Free Software Foundation, Inc.
+   Copyright (C) 1997, 1998, 1999 Free Software Foundation, Inc.
 
 This file is part of GNU CC.