Rollup merge of #21925 - sfackler:allow-missing-copy, r=alexcrichton

 This was particularly helpful in the time just after OIBIT's
implementation to make sure things that were supposed to be Copy
continued to be, but it's now creates a lot of noise for types that
intentionally don't want to be Copy.

r? @alexcrichton

Author: Manishearth

src/doc/reference.md

@@ -1813,7 +1813,6 @@ default visibility with the `priv` keyword. When an item is declared as `pub`,
 it can be thought of as being accessible to the outside world. For example:
 
 ```
-# #![allow(missing_copy_implementations)]
 # fn main() {}
 // Declare a private struct
 struct Foo;

src/libcollections/string.rs

@@ -49,7 +49,6 @@ pub struct FromUtf8Error {
 
 /// A possible error value from the `String::from_utf16` function.
 #[stable(feature = "rust1", since = "1.0.0")]
-#[allow(missing_copy_implementations)]
 #[derive(Debug)]
 pub struct FromUtf16Error(());
 

src/libcore/hash/sip.rs

@@ -30,7 +30,6 @@ use super::{Hasher, Writer};
 /// strong, this implementation has not been reviewed for such purposes.
 /// As such, all cryptographic uses of this implementation are strongly
 /// discouraged.
-#[allow(missing_copy_implementations)]
 pub struct SipHasher {
     k0: u64,
     k1: u64,

src/libcore/marker.rs

@@ -396,7 +396,6 @@ pub struct InvariantLifetime<'a>;
            reason = "likely to change with new variance strategy")]
 #[lang="no_copy_bound"]
 #[derive(Clone, PartialEq, Eq, PartialOrd, Ord)]
-#[allow(missing_copy_implementations)]
 pub struct NoCopy;
 
 /// A type which is considered managed by the GC. This is typically
@@ -405,5 +404,4 @@ pub struct NoCopy;
            reason = "likely to change with new variance strategy")]
 #[lang="managed_bound"]
 #[derive(Clone, PartialEq, Eq, PartialOrd, Ord)]
-#[allow(missing_copy_implementations)]
 pub struct Managed;

src/libcore/str/mod.rs

@@ -149,7 +149,6 @@ impl FromStr for bool {
 
 /// An error returned when parsing a `bool` from a string fails.
 #[derive(Debug, Clone, PartialEq)]
-#[allow(missing_copy_implementations)]
 #[stable(feature = "rust1", since = "1.0.0")]
 pub struct ParseBoolError { _priv: () }
 

src/liblibc/lib.rs

@@ -332,15 +332,12 @@ pub mod types {
             /// variants, because the compiler complains about the repr attribute
             /// otherwise.
             #[repr(u8)]
-            #[allow(missing_copy_implementations)]
             pub enum c_void {
                 __variant1,
                 __variant2,
             }
 
-            #[allow(missing_copy_implementations)]
             pub enum FILE {}
-            #[allow(missing_copy_implementations)]
             pub enum fpos_t {}
         }
         pub mod c99 {
@@ -354,9 +351,7 @@ pub mod types {
             pub type uint64_t = u64;
         }
         pub mod posix88 {
-            #[allow(missing_copy_implementations)]
             pub enum DIR {}
-            #[allow(missing_copy_implementations)]
             pub enum dirent_t {}
         }
         pub mod posix01 {}

src/librand/lib.rs

@@ -387,7 +387,6 @@ pub trait SeedableRng<Seed>: Rng {
 /// [1]: Marsaglia, George (July 2003). ["Xorshift
 /// RNGs"](http://www.jstatsoft.org/v08/i14/paper). *Journal of
 /// Statistical Software*. Vol. 8 (Issue 14).
-#[allow(missing_copy_implementations)]
 #[derive(Clone)]
 pub struct XorShiftRng {
     x: u32,

src/librustc/lint/builtin.rs

@@ -2038,7 +2038,7 @@ declare_lint! {
 
 declare_lint! {
     pub MISSING_COPY_IMPLEMENTATIONS,
-    Warn,
+    Allow,
     "detects potentially-forgotten implementations of `Copy`"
 }
 

src/librustc/middle/infer/region_inference/mod.rs

@@ -224,7 +224,6 @@ pub struct RegionVarBindings<'a, 'tcx: 'a> {
 }
 
 #[derive(Debug)]
-#[allow(missing_copy_implementations)]
 pub struct RegionSnapshot {
     length: uint,
     skolemization_count: u32,

src/librustc/middle/traits/coherence.rs

@@ -59,7 +59,6 @@ pub fn impl_can_satisfy(infcx: &InferCtxt,
             |o| selcx.evaluate_obligation(o))
 }
 
-#[allow(missing_copy_implementations)]
 pub enum OrphanCheckErr<'tcx> {
     NoLocalInputType,
     UncoveredTy(Ty<'tcx>),