Update accordingly with bux 1.12.0

1. [Change] Newly added log level LL_DEBUG can affect generated code.

Time to say goodbye to `fmt`

1.7.5

[Change] Reparsed by parsergen v1.7.5

Update with `fmt` & a couple of new flags

1. [New] %SUPPRESS_GLR_CONFLICTS to suppress printing all conflict actions which flips the target parser from LR1 into GLR.
2. [New] Command line flag --with-bom prefixes BOM to all output files.
3. [Change] Adapt to changes of fmt.
4. [Change] Use hyphen(-) instead of underline(_) to name long command flags.

[Bug] Input files in utf-16 may hit EOF earlier than expected

1. [Bug] Input files (eg. grammar) encoded in utf-16 may hit EOF earlier than it should when the first byte value '\x1a' is encountered.

Update with `bux` 1.6.5 due to include breakage

1. Include breakage
2. Fetch content of dependent bux with a fixed tag (1.6.5 for now), used for future detection of dependent ABI breakage.

Bugfixes & dependency update

1. [Dependency] Remove calls to FMT_STRING() with advent of fmt v8.x
2. [Dependency] Updates according to new g++ releases from 10.x
3. [Bug] Generated calls to createLex() should be bux::-qualified.
4. [Bug] Generate $c to a parenthesized expression to safely concatenate member reference with '.'
5. [Bug] Build fails when FETCH_DEPENDEES is defined in CMakeLists.txt (Main use case: AUR build)

Goodies

1. 🆕 parsergen & scannergen flag -a to say yes to all overwrites upon outputting.
2. 🆕 scannergen warns duplicated token definitions.
3. ✍️ Replace include guards with #pragma once
4. ✍️ Grammar files & token files are read as being prepended #pragma once. There is no way to turn this off until some use cases are
   observed.
5. ✍️ (scannergen) [[nodiscard]] for non-void methods of C_Context.
6. ✍️ (scannergen) C_Context::getOptionString return std::optional<std::string> instead of bool.

Warning-free clang build

1. ✍️ Stop using [[unlikely]] until clang-12 is available.
2. ✍️ Eliminate clang warnings here & there.

Backward incompatible release (all grammars have to be regenerated) according bux v1.2.1

1. 🆕 Issure errors when reserved nonterminals <@keyword> or <@operator> appears on left side of production.
2. ✍️ Use FMT_STRING() everywhere.
3. ✍️ Define ZIP_TOKEN() as constexpr function instead of macro.
4. ✍️ Rename all issueError() methods to log()
5. ✍️ Some function arg types from const std::string & to std::string_view
6. ✍️ Improve output readability & consistency
7. ✍️ No more update pkgver of test/archlinux/PKGBUILD for new releases.

Error recovery & reporting is ready for parsergen

1. 🆕 Add more constinit to in-module arrays of generated scanner code by scannergen
2. 🆕 New paragraph "Error Recovery & Parser Logger" to ParserGen/README.adoc
3. ✍️ Continuing upgrade of legacy code to Modern C++
4. ✍️ Issue "Template args not allowed" error when template args, disabled long time ago, is defined in class statement of grammar.txt
5. ✍️ Eliminate duplicated reduction code
6. ✍️ Examples re-generated by parsergen v1.6.1 & scannergen v1.5.1
7. ✍️ Simplified scannergen's grammar.txt
8. ✍️ Value of %NAMESPACE can be prefixed by ::