Some improvements to the Cargo compiler file.
Use rustc's errorformat and add option to specify permanent parameters.
Updates based on kballard's feedback.
Added check for absolute file path, removed hard tab, and added documentation for new option.
rust-mode.el: Tweak syntax table

"_" should keep the default syntax class (symbol, not word). This
allows, e.g., `forward-word' to behave in the familiar way, jumping to
underscores within a function or variable name.
Adding switch in vim plugin to toggle format opts
Add myself as an author
Rename json::List to json::Array

Fixes #19010
Fix some English spelling errors
mk/cfg: add .mk suffix on files to avoid "supprises" when backup files (file~) are in the directory
removed usage of struct_variant feature as it is no longer gated
removed struct_variant feature from tests
Update the Vim syntax prelude.
fixed markdown rendering a H1 in comment
test/run-make: some test cases lacked $(EXTRACFLAGS).

Signed-off-by: NODA, Kai <nodakai@gmail.com>
Removed unneeded conversion to a slice.

Vec<T> can index now so its a useless conversion.
doc: adding example for type definitions
Add comment on why `RefCell::unwrap` is safe
Add Utf16Encoder. Generalize Utf16CodeUnits for any Iterator<char>.

This allows encoding to UTF-16 something that is not in UTF-8, e.g. a
`[char]` UTF-32 string.

This might help with https://github.com/servo/servo/issues/4023
Implement BorrowFrom<&'a T> for T (with mutable variants)