declare 1-bit bitfields to be unsigned

As "gcc -pedantic" notices, a two's complement 1-bit signed integer
cannot represent the value '1'.

 dir.c: In function 'init_pathspec':
 dir.c:1291:4: warning: overflow in implicit constant conversion [-Woverflow]

In the spirit of v1.7.1-rc1~10 (2010-04-06), 'unsigned' is what was
intended, so let's make the flags unsigned.

Signed-off-by: Jonathan Nieder <jrnieder@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

cache.h

@@ -503,13 +503,13 @@ extern int ie_modified(const struct index_state *, struct cache_entry *, struct
 struct pathspec {
 	const char **raw; /* get_pathspec() result, not freed by free_pathspec() */
 	int nr;
-	int has_wildcard:1;
-	int recursive:1;
+	unsigned int has_wildcard:1;
+	unsigned int recursive:1;
 	int max_depth;
 	struct pathspec_item {
 		const char *match;
 		int len;
-		int has_wildcard:1;
+		unsigned int has_wildcard:1;
 	} *items;
 };