* lang_php/parsing/conflicts.txt:
[pfff] support for short lambda, part1, just parsing

Test Plan:
unit test included

Also applied the parser to jordan test files in hack:
$ ~/pfff/pfff -parse_php lambda*

 = File "lambda02.php", line 4, column 14,  charpos = 53
    around = ';', whole content =   $x = $y ==> ; // parse error: expected expression
badcount: 4
bad: <?hh // strict
bad:
bad: function foo(): void {
BAD:!!!!!   $x = $y ==> ; // parse error: expected expression
bad: }
[1G[m3 / 17[0m[1G[m4 / 17[0m[1G[m5 / 17[0mparse error
 = File "lambda05.php", line 4, column 32,  charpos = 71
    around = '}', whole content =   $x = ($x, $y) ==> { return $x }; // expected ;
badcount: 4
bad: <?hh // strict
bad:
bad: function foo(): void {
BAD:!!!!!   $x = ($x, $y) ==> { return $x }; // expected ;
bad: }

which seems good.

Reviewers: jdelong, julienv, andrewparoski

Reviewed By: andrewparoski

CC: jcreed, bryano, amenghra

Differential Revision: https://phabricator.fb.com/D1153411

Task ID: 3622749
[pfff] support for short lambda, part2, CST and AST changes

Test Plan: make test

Reviewers: andrewparoski, jdelong, julienv

Reviewed By: andrewparoski

CC: jcreed, bryano, amenghra, platform-diffs@lists

Differential Revision: https://phabricator.fb.com/D1156506

Task ID: 3622749
Merge branch 'master' of github.com:facebook/pfff