runtime(c): Update syntax and ftplugin files
- highlight more C keywords, including some from C23
Conditionally highlight C23 features:
- #embed, #elifdef and #elifndef preprocessor directives
- predefined macros
- UTF-8 character constants
- binary integer constants, _BitInt literals, and digit separators
- nullptr_t type and associated constant
- decimal real floating-point, bit precise and char types
- typeof operators
Matchit:
- update for new preprocessor directives
fixes: #13667
fixes: #13679
closes: #12984
Co-authored-by: Albin Ahlbäck <albin.ahlback@gmail.com>
Signed-off-by: Doug Kearns <dougkearns@gmail.com>
Signed-off-by: Christian Brabandt <cb@256bit.org>
diff --git a/runtime/doc/syntax.txt b/runtime/doc/syntax.txt
index 2fb320e..9b20478 100644
--- a/runtime/doc/syntax.txt
+++ b/runtime/doc/syntax.txt
@@ -1062,6 +1062,7 @@
*c_no_cformat* don't highlight %-formats in strings
*c_no_c99* don't highlight C99 standard items
*c_no_c11* don't highlight C11 standard items
+*c_no_c23* don't highlight C23 standard items
*c_no_bsd* don't highlight BSD specific types
*c_functions* highlight function calls and definitions
*c_function_pointers* highlight function pointers definitions