Update src/stable/lex.js

Modified match for smarttabs to ignore both single line comments and multiline comment blocks (as marked by a leading * character).
Fixed accessing left.immed without check if left is object
Fixed exprs[0].id sometimes causes undefined object error
Added destructured assign methods for DA recognition and association with values
updated const statement assignment function for destructured assign support
added var statement assignment function for destructured assign support
extracted destructuring assignment function out of useesnextsyntax function. And renamed the functions to destructuring expressions.
added support for destructured syntax in functions parameters
adding destructuring assignment without a prefix token for #883
fixed error reporting on destructuring expression on non-existing variables (made it a W117 instead of a jsonvalue error) for #883.
fixed left variable checking in infix() function, to avoid throwing exceptions if left is undefined.
removed useless property setting
fixed errors and typos in committed patches for #883.
updated style
changed first comment to avoid unintended annoying warning about " global ".
fix conditions for square bracket evaluation as destructuring assign for #883
added support for encapsulated destructuring expressions
fixed the use of extracted identifiers to match/support destructuring arrays with empty values.
minor refactoring for JSON parsing
added destructuring expression tests