[9fans] compiler bug

[Mike Haertel <mike@ducky.net>]

Under pcc, the following program:

	#include <stdio.h>
	#include <stdlib.h>

	int
	main()
	{
		printf("%d\n", (int) (0x80000000 >> 31));
		exit(EXIT_SUCCESS);
	}

prints -1.  It should print 1.  According to ANSI C (either version,
take your pick: c89, section 3.1.3.2, or c99, section 6.4.4.1) hex
and octal constants take on the first type in the list: int, unsigned
int, long, unsigned long, etc. in which their value is representable.

In this case, 0x80000000 is not a representable value of type int,
but is representable as unsigned int, so it should have that type.

This bit me today when some of the initializers of an "unsigned long long"
array mysteriously got sign extended from 32 bits.