relibc: complete round-9 fixes and repair ifaddrs compilation

Builds on a41c5cb0 (round-9 stub replacements) with three enhancements
and a critical compilation fix:

1. getrusage (platform/redox/mod.rs): Extended ProcStatFields to parse
   minflt (field 7) and majflt (field 9) from the kernel proc scheme
   stat line. These fields are present in the Linux-compatible stat
   format but currently hardwired to zero by the kernel; relibc now
   parses and forwards them so they report real values automatically
   when the kernel starts tracking them. inblock/oublock/nvcsw/nivcsw
   remain zero (not present in the proc stat line). clock_settime stub
   (todo_skip!) replaced with real syscall::syscall2(SYS_CLOCK_SETTIME).

2. pthread_condattr_setclock (pthread/cond.rs): Added
   CLOCK_PROCESS_CPUTIME_ID (value 2, defined in constants.rs) to the
   accepted clock list alongside CLOCK_REALTIME and CLOCK_MONOTONIC.
   CLOCK_THREAD_CPUTIME_ID, CLOCK_REALTIME_COARSE, and
   CLOCK_MONOTONIC_COARSE are not defined on Redox so cannot be
   accepted.

3. ifaddrs (header/ifaddrs/mod.rs): Fixed 7 pre-existing compilation
   errors that blocked the entire relibc library from compiling.
   The module was introduced in d9760bdc but never compiled: wrong
   imports (AF_INET from netinet_in instead of sys_socket, sa_family_t
   from sys_socket instead of bits_safamily_t, nonexistent AF_PACKET),
   missing Vec import, copy_nonoverlapping direction reversed (copied
   FROM zeroed sockaddr INTO source data), prefix validation inverted
   (rejected all valid 0-128 values), IPv6 address bytes never copied
   into sockaddr_in6, edition-2024 unsafe-block requirements.

src/platform/redox/mod.rs

@@ -109,12 +109,17 @@ const fn default_rlimits() -> [rlimit; RLIM_COUNT] {
 
 /// Fields parsed from the kernel proc scheme's Linux-compatible stat line,
 /// used by `getrusage`. The kernel reports `utime`/`stime` in whole seconds
-/// and `rss` in pages. Per-process fault and context-switch counters are
-/// currently hardwired to zero by the kernel proc scheme.
+/// and `rss` in pages. The kernel currently hardwires fault counters
+/// (`minflt`/`majflt`) to zero, but relibc parses them so they will be
+/// reported automatically once the kernel starts tracking real values.
+/// Context-switch and I/O counters (`inblock`, `oublock`, `nvcsw`,
+/// `nivcsw`) are not present in the proc stat line at all.
 struct ProcStatFields {
     utime_sec: u64,
     stime_sec: u64,
     rss_pages: u64,
+    minflt: u64,
+    majflt: u64,
 }
 
 /// Read and parse `/scheme/proc/<pid>/stat` from the kernel proc scheme.
@@ -156,6 +161,8 @@ fn read_proc_stat_fields(pid: usize) -> Option<ProcStatFields> {
         utime_sec: parse(11)?,
         stime_sec: parse(12)?,
         rss_pages: parse(21).unwrap_or(0),
+        minflt: parse(7).unwrap_or(0),
+        majflt: parse(9).unwrap_or(0),
     })
 }
 
@@ -324,8 +331,20 @@ impl Pal for Sys {
     }
 
     unsafe fn clock_settime(clk_id: clockid_t, tp: *const timespec) -> Result<()> {
-        todo_skip!(0, "clock_settime({}, {:p}): not implemented", clk_id, tp);
-        Err(Errno(ENOSYS))
+        if tp.is_null() {
+            return Err(Errno(EINVAL));
+        }
+        let relibc_ts = unsafe { &*tp };
+        let redox_tp = syscall::TimeSpec {
+            tv_sec: relibc_ts.tv_sec as i64,
+            tv_nsec: relibc_ts.tv_nsec as i64,
+        };
+        syscall::syscall2(
+            syscall::SYS_CLOCK_SETTIME,
+            clk_id as usize,
+            &redox_tp as *const _ as usize,
+        )?;
+        Ok(())
     }
 
     fn close(fd: c_int) -> Result<()> {
@@ -886,6 +905,8 @@ impl Pal for Sys {
             utime_sec: 0,
             stime_sec: 0,
             rss_pages: 0,
+            minflt: 0,
+            majflt: 0,
         });
 
         // ru_maxrss is in kilobytes (Linux convention); rss from the stat
@@ -905,10 +926,12 @@ impl Pal for Sys {
             ru_ixrss: 0,
             ru_idrss: 0,
             ru_isrss: 0,
-            // The kernel proc scheme hardwires fault counters to zero today.
-            ru_minflt: 0,
-            ru_majflt: 0,
+            ru_minflt: stat.minflt as c_long,
+            ru_majflt: stat.majflt as c_long,
             ru_nswap: 0,
+            // The proc stat line does not include I/O or context-switch
+            // counters; these require /proc/<pid>/io or /proc/<pid>/status
+            // interfaces that the Redox proc scheme does not expose today.
             ru_inblock: 0,
             ru_oublock: 0,
             ru_msgsnd: 0,