bitset: expand bit index type to `long`

An upcoming patch to use the bitset macros for tracking vm page
dump information could conceivably need more than INT_MAX bits.
Expand the bit type to long so that the extra range is available
on 64-bit platforms where it would most likely be needed.

CPUSET_COUNT and DOMAINSET_COUNT are also modified to remain of
type `int`.

Reviewed by:	kib, markj
Approved by:	scottl (implicit)
MFC after:	1 week
Sponsored by:	Ampere Computing, Inc.
Differential Revision:	https://reviews.freebsd.org/D26190

newlib/libc/sys/rtems/include/sys/bitset.h

@@ -216,8 +216,7 @@
  */
 #define	BIT_FFS_AT(_s, p, start) __extension__ ({			\
 	__size_t __i;							\
-	long __mask;							\
-	int __bit;							\
+	long __bit, __mask;						\
 									\
 	__mask = ~0UL << ((start) % _BITSET_BITS);			\
 	__bit = 0;							\
@@ -238,7 +237,7 @@
 
 #define	BIT_FLS(_s, p) __extension__ ({					\
 	__size_t __i;							\
-	int __bit;							\
+	long __bit;							\
 									\
 	__bit = 0;							\
 	for (__i = __bitset_words((_s)); __i > 0; __i--) {		\
@@ -253,7 +252,7 @@
 
 #define	BIT_COUNT(_s, p) __extension__ ({				\
 	__size_t __i;							\
-	int __count;							\
+	long __count;							\
 									\
 	__count = 0;							\
 	for (__i = 0; __i < __bitset_words((_s)); __i++)		\

newlib/libc/sys/rtems/include/sys/cpuset.h

@@ -191,7 +191,7 @@ static __inline void CPU_ANDNOT(cpu_set_t *destset, const cpu_set_t *srcset1,
 
 static __inline int CPU_COUNT_S(size_t setsize, const cpu_set_t *set)
 {
-  return BIT_COUNT(_cpu_set_bits(setsize), set);
+  return (int)BIT_COUNT(_cpu_set_bits(setsize), set);
 }
 
 static __inline int CPU_COUNT(const cpu_set_t *set)