revert some more constification.

src/libstd/io/cursor.rs

@@ -104,7 +104,7 @@ impl<T> Cursor<T> {
     /// # force_inference(&buff);
     /// ```
     #[stable(feature = "rust1", since = "1.0.0")]
-    pub const fn new(inner: T) -> Cursor<T> {
+    pub fn new(inner: T) -> Cursor<T> {
         Cursor { pos: 0, inner: inner }
     }
 
@@ -138,7 +138,7 @@ impl<T> Cursor<T> {
     /// let reference = buff.get_ref();
     /// ```
     #[stable(feature = "rust1", since = "1.0.0")]
-    pub const fn get_ref(&self) -> &T { &self.inner }
+    pub fn get_ref(&self) -> &T { &self.inner }
 
     /// Gets a mutable reference to the underlying value in this cursor.
     ///
@@ -179,7 +179,7 @@ impl<T> Cursor<T> {
     /// assert_eq!(buff.position(), 1);
     /// ```
     #[stable(feature = "rust1", since = "1.0.0")]
-    pub const fn position(&self) -> u64 { self.pos }
+    pub fn position(&self) -> u64 { self.pos }
 
     /// Sets the position of this cursor.
     ///

src/libstd/io/mod.rs

@@ -885,7 +885,7 @@ impl Initializer {
     /// Returns a new `Initializer` which will zero out buffers.
     #[unstable(feature = "read_initializer", issue = "42788")]
     #[inline]
-    pub const fn zeroing() -> Initializer {
+    pub fn zeroing() -> Initializer {
         Initializer(true)
     }
 
@@ -906,7 +906,7 @@ impl Initializer {
     /// Indicates if a buffer should be initialized.
     #[unstable(feature = "read_initializer", issue = "42788")]
     #[inline]
-    pub const fn should_initialize(&self) -> bool {
+    pub fn should_initialize(&self) -> bool {
         self.0
     }
 

src/libstd/io/util.rs

@@ -99,7 +99,7 @@ pub struct Empty { _priv: () }
 /// assert!(buffer.is_empty());
 /// ```
 #[stable(feature = "rust1", since = "1.0.0")]
-pub const fn empty() -> Empty { Empty { _priv: () } }
+pub fn empty() -> Empty { Empty { _priv: () } }
 
 #[stable(feature = "rust1", since = "1.0.0")]
 impl Read for Empty {
@@ -199,7 +199,7 @@ pub struct Sink { _priv: () }
 /// assert_eq!(num_bytes, 5);
 /// ```
 #[stable(feature = "rust1", since = "1.0.0")]
-pub const fn sink() -> Sink { Sink { _priv: () } }
+pub fn sink() -> Sink { Sink { _priv: () } }
 
 #[stable(feature = "rust1", since = "1.0.0")]
 impl Write for Sink {

src/libstd/process.rs

@@ -926,7 +926,7 @@ impl Stdio {
     /// assert_eq!(String::from_utf8_lossy(&output.stdout), "!dlrow ,olleH\n");
     /// ```
     #[stable(feature = "process", since = "1.0.0")]
-    pub const fn piped() -> Stdio { Stdio(imp::Stdio::MakePipe) }
+    pub fn piped() -> Stdio { Stdio(imp::Stdio::MakePipe) }
 
     /// The child inherits from the corresponding parent descriptor.
     ///
@@ -961,7 +961,7 @@ impl Stdio {
     /// println!("You piped in the reverse of: {}", String::from_utf8_lossy(&output.stdout));
     /// ```
     #[stable(feature = "process", since = "1.0.0")]
-    pub const fn inherit() -> Stdio { Stdio(imp::Stdio::Inherit) }
+    pub fn inherit() -> Stdio { Stdio(imp::Stdio::Inherit) }
 
     /// This stream will be ignored. This is the equivalent of attaching the
     /// stream to `/dev/null`
@@ -998,7 +998,7 @@ impl Stdio {
     /// // Ignores any piped-in input
     /// ```
     #[stable(feature = "process", since = "1.0.0")]
-    pub const fn null() -> Stdio { Stdio(imp::Stdio::Null) }
+    pub fn null() -> Stdio { Stdio(imp::Stdio::Null) }
 }
 
 impl FromInner<imp::Stdio> for Stdio {

src/libstd/thread/mod.rs

@@ -286,7 +286,7 @@ impl Builder {
     /// handler.join().unwrap();
     /// ```
     #[stable(feature = "rust1", since = "1.0.0")]
-    pub const fn new() -> Builder {
+    pub fn new() -> Builder {
         Builder {
             name: None,
             stack_size: None,