Check improper delete array

Hi Clang,

The attached patch adds a Checker to clang, it checks improper uses of delete operator(now using delete instead of delete to delete an array). I add poststmt check to VisitCXXNewExpr and prestmt check to VisitCXXDeleteExpr.

I will appreciate it if there are any advice about this patch.

Delete.patch (5.2 KB)