rollup merge of #20481: seanmonstar/fmt-show-string

Conflicts:
	src/compiletest/runtest.rs
	src/libcore/fmt/mod.rs
	src/libfmt_macros/lib.rs
	src/libregex/parse.rs
	src/librustc/middle/cfg/construct.rs
	src/librustc/middle/dataflow.rs
	src/librustc/middle/infer/higher_ranked/mod.rs
	src/librustc/middle/ty.rs
	src/librustc_back/archive.rs
	src/librustc_borrowck/borrowck/fragments.rs
	src/librustc_borrowck/borrowck/gather_loans/mod.rs
	src/librustc_resolve/lib.rs
	src/librustc_trans/back/link.rs
	src/librustc_trans/save/mod.rs
	src/librustc_trans/trans/base.rs
	src/librustc_trans/trans/callee.rs
	src/librustc_trans/trans/common.rs
	src/librustc_trans/trans/consts.rs
	src/librustc_trans/trans/controlflow.rs
	src/librustc_trans/trans/debuginfo.rs
	src/librustc_trans/trans/expr.rs
	src/librustc_trans/trans/monomorphize.rs
	src/librustc_typeck/astconv.rs
	src/librustc_typeck/check/method/mod.rs
	src/librustc_typeck/check/mod.rs
	src/librustc_typeck/check/regionck.rs
	src/librustc_typeck/collect.rs
	src/libsyntax/ext/format.rs
	src/libsyntax/ext/source_util.rs
	src/libsyntax/ext/tt/transcribe.rs
	src/libsyntax/parse/mod.rs
	src/libsyntax/parse/token.rs
	src/test/run-pass/issue-8898.rs

src/libstd/io/mod.rs

@@ -302,7 +302,7 @@ pub type IoResult<T> = Result<T, IoError>;
 /// # FIXME
 ///
 /// Is something like this sufficient? It's kind of archaic
-#[derive(PartialEq, Eq, Clone)]
+#[derive(PartialEq, Eq, Clone, Show)]
 pub struct IoError {
     /// An enumeration which can be matched against for determining the flavor
     /// of error.
@@ -339,7 +339,7 @@ impl IoError {
     }
 }
 
-impl fmt::Show for IoError {
+impl fmt::String for IoError {
     fn fmt(&self, fmt: &mut fmt::Formatter) -> fmt::Result {
         match *self {
             IoError { kind: OtherIoError, desc: "unknown error", detail: Some(ref detail) } =>
@@ -1656,7 +1656,7 @@ pub fn standard_error(kind: IoErrorKind) -> IoError {
 /// A mode specifies how a file should be opened or created. These modes are
 /// passed to `File::open_mode` and are used to control where the file is
 /// positioned when it is initially opened.
-#[derive(Copy, Clone, PartialEq, Eq)]
+#[derive(Copy, Clone, PartialEq, Eq, Show)]
 pub enum FileMode {
     /// Opens a file positioned at the beginning.
     Open,
@@ -1668,7 +1668,7 @@ pub enum FileMode {
 
 /// Access permissions with which the file should be opened. `File`s
 /// opened with `Read` will return an error if written to.
-#[derive(Copy, Clone, PartialEq, Eq)]
+#[derive(Copy, Clone, PartialEq, Eq, Show)]
 pub enum FileAccess {
     /// Read-only access, requests to write will result in an error
     Read,
@@ -1825,6 +1825,12 @@ impl Default for FilePermission {
 }
 
 impl fmt::Show for FilePermission {
+    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+        fmt::String::fmt(self, f)
+    }
+}
+
+impl fmt::String for FilePermission {
     fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
         write!(f, "{:04o}", self.bits)
     }