Rename methods to clearly signal when they only deal with ASCII,
simplify the parsing of identifier, and use start/continue instead of
head/body for consistency with Unicode terminology.
Adds the `between` combinator and registers it with the parser. As a driveby, updates some deprecated names to their current versions.
Reviewed By: gribozavr2
Differential Revision: https://reviews.llvm.org/D84315
This patch adds a parser for a `RangeSelector` written as a string. The format
is closely based on the way one would right the selector in C++. This should
enable use of `RangeSelector`s from tools like clang-query and web UIs.