[Tolk] Initial commit of TOLK Language: fork all sources from FunC

The Tolk Language will be positioned as "next-generation FunC".
It's literally a fork of a FunC compiler,
introducing familiar syntax similar to TypeScript,
but leaving all low-level optimizations untouched.

Note, that FunC sources are partially stored
in the parser/ folder (shared with TL/B).
In Tolk, nothing is shared.
Everything from parser/ is copied into tolk/ folder.

tolk/tolk-main.cpp

@@ -0,0 +1,122 @@
+/*
+    This file is part of TON Blockchain source code.
+
+    TON Blockchain is free software; you can redistribute it and/or
+    modify it under the terms of the GNU General Public License
+    as published by the Free Software Foundation; either version 2
+    of the License, or (at your option) any later version.
+
+    TON Blockchain is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+    GNU General Public License for more details.
+
+    You should have received a copy of the GNU General Public License
+    along with TON Blockchain.  If not, see <http://www.gnu.org/licenses/>.
+
+    In addition, as a special exception, the copyright holders give permission
+    to link the code of portions of this program with the OpenSSL library.
+    You must obey the GNU General Public License in all respects for all
+    of the code used other than OpenSSL. If you modify file(s) with this
+    exception, you may extend this exception to your version of the file(s),
+    but you are not obligated to do so. If you do not wish to do so, delete this
+    exception statement from your version. If you delete this exception statement
+    from all source files in the program, then also delete it here.
+*/
+#include "tolk.h"
+#include <getopt.h>
+#include <fstream>
+#include "git.h"
+
+void usage(const char* progname) {
+  std::cerr
+      << "usage: " << progname
+      << " [-vIAPSR][-O<level>][-i<indent-spc>][-o<output-filename>][-W<boc-filename>] {<filename.tolk> ...}\n"
+         "\tGenerates Fift TVM assembler code from a Tolk source\n"
+         "-I\tEnables interactive mode (parse stdin)\n"
+         "-o<fift-output-filename>\tWrites generated code into specified file instead of stdout\n"
+         "-v\tIncreases verbosity level (extra information output into stderr)\n"
+         "-i<indent>\tSets indentation for the output code (in two-space units)\n"
+         "-A\tPrefix code with `\"Asm.fif\" include` preamble\n"
+         "-O<level>\tSets optimization level (2 by default)\n"
+         "-P\tEnvelope code into PROGRAM{ ... }END>c\n"
+         "-S\tInclude stack layout comments in the output code\n"
+         "-R\tInclude operation rewrite comments in the output code\n"
+         "-W<output-boc-file>\tInclude Fift code to serialize and save generated code into specified BoC file. Enables "
+         "-A and -P.\n"
+         "\t-s\tOutput semantic version of Tolk and exit\n"
+         "\t-V<version>\tShow Tolk build information\n";
+  std::exit(2);
+}
+
+int main(int argc, char* const argv[]) {
+  int i;
+  std::string output_filename;
+  while ((i = getopt(argc, argv, "Ahi:Io:O:PRsSvW:V")) != -1) {
+    switch (i) {
+      case 'A':
+        tolk::asm_preamble = true;
+        break;
+      case 'I':
+        tolk::interactive = true;
+        break;
+      case 'i':
+        tolk::indent = std::max(0, atoi(optarg));
+        break;
+      case 'o':
+        output_filename = optarg;
+        break;
+      case 'O':
+        tolk::opt_level = std::max(0, atoi(optarg));
+        break;
+      case 'P':
+        tolk::program_envelope = true;
+        break;
+      case 'R':
+        tolk::op_rewrite_comments = true;
+        break;
+      case 'S':
+        tolk::stack_layout_comments = true;
+        break;
+      case 'v':
+        ++tolk::verbosity;
+        break;
+      case 'W':
+        tolk::boc_output_filename = optarg;
+        tolk::asm_preamble = tolk::program_envelope = true;
+        break;
+      case 's':
+        std::cout << tolk::tolk_version << "\n";
+        std::exit(0);
+      case 'V':
+        std::cout << "Tolk semantic version: v" << tolk::tolk_version << "\n";
+        std::cout << "Build information: [ Commit: " << GitMetadata::CommitSHA1() << ", Date: " << GitMetadata::CommitDate() << "]\n";
+        std::exit(0);
+      case 'h':
+      default:
+        usage(argv[0]);
+    }
+  }
+
+  std::ostream *outs = &std::cout;
+
+  std::unique_ptr<std::fstream> fs;
+  if (!output_filename.empty()) {
+    fs = std::make_unique<std::fstream>(output_filename, std::fstream::trunc | std::fstream::out);
+    if (!fs->is_open()) {
+      std::cerr << "failed to create output file " << output_filename << '\n';
+      return 2;
+    }
+    outs = fs.get();
+  }
+
+  std::vector<std::string> sources;
+
+  while (optind < argc) {
+    sources.push_back(std::string(argv[optind++]));
+  }
+
+  tolk::read_callback = tolk::fs_read_callback;
+
+  return tolk::tolk_proceed(sources, *outs, std::cerr);
+}