std: Avoid using "{:?}" in format strings

This removes all usage of Poly in format strings from libstd. This doesn't
prevent more future strings from coming in, but it at least removes the ones for
now.

src/libnative/io/process.rs

@@ -470,7 +470,7 @@ unsafe fn set_cloexec(fd: c_int) {
                 Err(e) => {
                     assert!(e.kind == io::BrokenPipe ||
                             e.kind == io::EndOfFile,
-                            "unexpected error: {:?}", e);
+                            "unexpected error: {}", e);
                     Ok(SpawnProcessResult {
                         pid: pid,
                         handle: ptr::null()
@@ -744,7 +744,7 @@ pub fn WTERMSIG(status: i32) -> i32 { status & 0o177 }
 
         let mut status = 0 as c_int;
         match retry(|| unsafe { wait::waitpid(pid, &mut status, 0) }) {
-            -1 => fail!("unknown waitpid error: {:?}", super::last_error()),
+            -1 => fail!("unknown waitpid error: {}", super::last_error()),
             _ => {
                 if imp::WIFEXITED(status) {
                     p::ExitStatus(imp::WEXITSTATUS(status) as int)

src/libstd/num/strconv.rs

@@ -532,19 +532,19 @@ pub fn from_str_bytes_common<T:NumCast+Zero+One+Eq+Ord+Div<T,T>+
         ) -> Option<T> {
     match exponent {
         ExpDec if radix >= DIGIT_E_RADIX       // decimal exponent 'e'
-          => fail!("from_str_bytes_common: radix {:?} incompatible with \
+          => fail!("from_str_bytes_common: radix {} incompatible with \
                     use of 'e' as decimal exponent", radix),
         ExpBin if radix >= DIGIT_P_RADIX       // binary exponent 'p'
-          => fail!("from_str_bytes_common: radix {:?} incompatible with \
+          => fail!("from_str_bytes_common: radix {} incompatible with \
                     use of 'p' as binary exponent", radix),
         _ if special && radix >= DIGIT_I_RADIX // first digit of 'inf'
-          => fail!("from_str_bytes_common: radix {:?} incompatible with \
+          => fail!("from_str_bytes_common: radix {} incompatible with \
                     special values 'inf' and 'NaN'", radix),
         _ if (radix as int) < 2
-          => fail!("from_str_bytes_common: radix {:?} to low, \
+          => fail!("from_str_bytes_common: radix {} to low, \
                     must lie in the range [2, 36]", radix),
         _ if (radix as int) > 36
-          => fail!("from_str_bytes_common: radix {:?} to high, \
+          => fail!("from_str_bytes_common: radix {} to high, \
                     must lie in the range [2, 36]", radix),
         _ => ()
     }