Update documentation for from_raw_parts

Fixes #19269.
Lifetime guide -> ownership guide
impl Clone for Cow
small doc fixes

We don't need this &mut, and vec could use []s
fix expand_quote_ty function as parse_ty was changed and needs no arguments now
Fix typo in reference.md
Allow trailing commas in array patterns and attributes
Simplify `RefCell` code a bit, make `deref` a no-op.
allow macro expansions in attributes
std: Remove implicit shrinking from hash_map.

Implements fn shrink_to_fit for HashMap.
std: Change the behavior of `reserve` for HashMap.

HashMap's `reserve` method now takes as an argument the *extra* space
to reserve.

[breaking-change]
std: add tests for the Vec<u8> Writer impl
std: add Reader impl for &[u8]
Add test for expanding doc strings in macros.
added negative test for macro expansion in attributes
test/run-make: another missing $(EXTRACFLAGS).

rust-lang/rust@102b1a5bf1a60eeafb752844e5c98fe5f4e3b992 was not enough!

Signed-off-by: NODA, Kai <nodakai@gmail.com>
debuginfo: Fix multi-byte character related bug in cleanup scope handling.

Also see issue #18791.
rustdoc: Check for href when prepending rootPath

Fixes #18354.
auto merge of #19427 : scialex/rust/doc-attr-macros, r=sfackler

this allows one to, for example, use #[doc = $macro_var ] in macros.
auto merge of #19357 : michaelwoerister/rust/fix-issue-18791, r=alexcrichton

One negative side-effect of this change is that there might be quite a bit of copying strings out of the codemap, i.e. one copy for every block that gets translated, just for taking a look at the last character of the block. If this turns out to cause a performance problem then `CodeMap::span_to_snippet()` could be changed return `Option<&str>` instead of `Option<String>`.

Fixes #18791