auto merge of #15493 : brson/rust/tostr, r=pcwalton

This updates https://github.com/rust-lang/rust/pull/15075.

Rename `ToStr::to_str` to `ToString::to_string`. The naive renaming ends up with two `to_string` functions defined on strings in the prelude (the other defined via `collections::str::StrAllocating`). To remedy this I removed `StrAllocating::to_string`, making all conversions from `&str` to `String` go through `Show`. This has a measurable impact on the speed of this conversion, but the sense I get from others is that it's best to go ahead and unify `to_string` and address performance for all `to_string` conversions in `core::fmt`. `String::from_str(...)` still works as a manual fast-path.

Note that the patch was done with a script, and ended up renaming a number of other `*_to_str` functions, particularly inside of rustc. All the ones I saw looked correct, and I didn't notice any additional API breakage.

Closes #15046.

1 files changed, 1 insertions, 1 deletions

diff --git a/src/test/debuginfo/cross-crate-type-uniquing.rs b/src/test/debuginfo/cross-crate-type-uniquing.rs
index 47de06c4856..8f718add2a3 100644
--- a/src/test/debuginfo/cross-crate-type-uniquing.rs
+++ b/src/test/debuginfo/cross-crate-type-uniquing.rs
@@ -21,4 +21,4 @@ pub fn p() -> C {
     C
 }
 
-fn main() { }
\ No newline at end of file
+fn main() { }