protoize duplicates 'const' on non-pointer function arguments

[Ken Raeburn]

% cat foo2.c
int func (a, b)
    int a;
    const int b;
{
    return a + b;
}
% protoize foo2.c
protoize: compiling `foo2.c'
protoize: converting file `foo2.c'
% cat foo2.c
int func (int a, const const int b)
{
    return a + b;
}
% gcc -c foo2.c
foo2.c:1: warning: duplicate `const'
% protoize -V
protoize: 3.2
% gcc -v
Reading specs from /var/raeburn/gcc-3.2/lib/gcc-lib/i686-pc-linux-gnu/3.2/specs
Configured with: ./configure --prefix=/var/raeburn/gcc-3.2
Thread model: posix
gcc version 3.2
%