Description:
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"Parser error" generated in dobule quoted strings, when after '->' operator there is double quote char ("). If next char after '->' isn't (") then parse error isn't generated.

Reproduce code:
---------------
// 1)
$a='ok';
echo "$a->-";
echo "$a-> -";

// 2) 
$a='ok';
echo "$a->";

Expected result:
----------------
// 1)
ok->-
ok-> -

// 2)
ok->

Actual result:
--------------
// 1) (This case works fine)
ok->-
ok-> -

// 2)
Parse error: parse error, expecting `T_STRING' in ...