function processVariableData(variableData, isDefault, ignoreDefaults) {
      return {
        defaultCount: isDefault
          ? ++variableData.defaultCount
          : variableData.defaultCount,
        isDeclared:
          isDefault && ignoreDefaults !== false ? variableData.isDeclared : true
      };
    }
Processes the variable data based on the given arguments.
@param {{ defaultCount: number; isDeclared: boolean; }} variableData the variable data
containing default count and if the variable is declared.
@param {boolean} isDefault if the variable contains the `!default` keyword.
@param {boolean | number} ignoreDefaults the ignore defaults options.
@returns the updated `variableData`.