message: Make functions in header source-compatible with old code.
  There might be old code that expects a certain amount of parameters.
  Add a default parameter for now to make these compatible.
diff: @@ -47,7 +47,7 @@ namespace verilog {
  // errors were found (syntax, lint), and anything else is a fatal error.
  int LintOneFile(std::ostream* stream, absl::string_view filename,
  const LinterConfiguration& config, bool check_syntax,
  - bool parse_fatal, bool lint_fatal, bool show_context);
  + bool parse_fatal, bool lint_fatal, bool show_context = false);
  // VerilogLinter analyzes a TextStructureView of Verilog source code.
  // This uses syntax-tree based analyses and lexical token-stream analyses.
  @@ -116,7 +116,8 @@ absl::Status AppendLinterConfigurationFromFile(
  absl::Status VerilogLintTextStructure(
  std::ostream* stream, const std::string& filename,
  const std::string& contents, const LinterConfiguration& config,
  - const verible::TextStructureView& text_structure, bool show_context);
  + const verible::TextStructureView& text_structure,
  + bool show_context = false);
  // Prints the rule, description and default_enabled.
  absl::Status PrintRuleInfo(std::ostream*,
  