Update c-lex.c copyright and description

[Neil Booth]

I've applied this.

Neil.

	* c-lex.c: Update copyright and file description.

Index: c-lex.c
===================================================================
RCS file: /cvs/gcc/gcc/gcc/c-lex.c,v
retrieving revision 1.181
diff -u -p -r1.181 c-lex.c
--- c-lex.c	2 Jun 2002 19:37:27 -0000	1.181
+++ c-lex.c	2 Jun 2002 20:12:11 -0000
@@ -1,6 +1,6 @@
-/* Lexical analyzer for C and Objective C.
+/* Mainly the interface between cpplib and the C front ends.
    Copyright (C) 1987, 1988, 1989, 1992, 1994, 1995, 1996, 1997
-   1998, 1999, 2000 Free Software Foundation, Inc.
+   1998, 1999, 2000, 2001, 2002 Free Software Foundation, Inc.
 
 This file is part of GCC.