Merge pull request #708 from viperproject/meilers_let_parse_fix

Fixing let parsing

Author: marcoeilers

src/main/scala/viper/silver/parser/FastParser.scala

@@ -975,7 +975,7 @@ class FastParser {
       FP("perm" ~ parens(resAcc)).map{ case (pos, r) => PCurPerm(r)(pos)})
 
   def let[$: P]: P[PExp] =
-    FP("let" ~/ FP(idndef) ~ "==" ~ "(" ~ exp ~ ")" ~ "in" ~ FP(exp)).map {
+    FP("let" ~ FP(idndef) ~ "==" ~/ "(" ~ exp ~ ")" ~ "in" ~ FP(exp)).map {
       case (pos, (idpos, id, exp1, (e2pos, exp2))) =>
       /* Type unresolvedType is expected to be replaced with the type of exp1
        * after the latter has been resolved