Microsoft/TypeScript — pull request #255 by JsonFreeman (2014-07-25 19:41:38+00:00)
Title: Improve the error in a 'for in' statement [#154]

We used to have errors that said:
"Variable declarations of a 'for' statement..."

But sometimes the left hand side of a for..in statement is an expression, not a variable statement. I've improved the error to say:
"Left hand side of a 'for' statement"