rollup merge of #24487: erickt/syntax

This removes the usage of `#[feature(into_cow, slice_patterns, box_syntax, box_patterns, quote, unsafe_destructor)]` from being used in libsyntax. My main desire for this is that it brings me one step closer to letting [syntex](https://github.com/erickt/rust-syntex) compile with stable rust. Hopefully this doesn't inconvenience rust development.

1 files changed, 1 insertions, 1 deletions

diff --git a/src/libsyntax/ptr.rs b/src/libsyntax/ptr.rs
index 5032cd57eeb..83e321f110c 100644
--- a/src/libsyntax/ptr.rs
+++ b/src/libsyntax/ptr.rs
@@ -52,7 +52,7 @@ pub struct P<T> {
 /// Construct a `P<T>` from a `T` value.
 pub fn P<T: 'static>(value: T) -> P<T> {
     P {
-        ptr: box value
+        ptr: Box::new(value)
     }
 }