Rename reserve_for_push to grow_one and fix comment.

library/alloc/src/collections/vec_deque/mod.rs

@@ -2087,7 +2087,7 @@ impl<T, A: Allocator> VecDeque<T, A> {
  // buffer without it being full emerge
  debug_assert!(self.is_full());
  let old_cap = self.capacity();
- self.buf.reserve_for_push();
+ self.buf.grow_one();
  unsafe {
  self.handle_capacity_increase(old_cap);
  }

library/alloc/src/raw_vec.rs

@@ -345,11 +345,11 @@ impl<T, A: Allocator> RawVec<T, A> {
  }
  }
 
- /// A specialized version of `reserve()` used only by the hot and
- /// oft-instantiated `Vec::push()`, which does its own capacity check.
+ /// A specialized version of `self.reserve(len, 1)` which requires the
+ /// caller to ensure `len == self.capacity()`.
  #[cfg(not(no_global_oom_handling))]
  #[inline(never)]
- pub fn reserve_for_push(&mut self) {
+ pub fn grow_one(&mut self) {
  if let Err(err) = self.grow_amortized(self.cap.0, 1) {
  handle_error(err);
  }

library/alloc/src/vec/mod.rs

@@ -1547,7 +1547,7 @@ impl<T, A: Allocator> Vec<T, A> {
 
  // space for the new element
  if len == self.buf.capacity() {
- self.buf.reserve_for_push();
+ self.buf.grow_one();
  }
 
  unsafe {
@@ -1967,7 +1967,7 @@ impl<T, A: Allocator> Vec<T, A> {
  // This will panic or abort if we would allocate > isize::MAX bytes
  // or if the length increment would overflow for zero-sized types.
  if self.len == self.buf.capacity() {
- self.buf.reserve_for_push();
+ self.buf.grow_one();
  }
  unsafe {
  let end = self.as_mut_ptr().add(self.len);