remove some unnecessary !! from stdlib

libraries/stdlib/test/regressions/Kt2495Test.kt

@@ -14,7 +14,7 @@ fun f(xs: Iterator<Int>): Int {
 class Kt2495Test {
     test fun duplicateIteratorsBug() {
         val list = arrayList(1, 2, 3)
-        val result = f(list.iterator()!!)
+        val result = f(list.iterator())
         assertEquals(6, result)
     }
 }

libraries/stdlib/test/regressions/kt1202.kt

@@ -99,7 +99,7 @@ fun parseAtomic(tokens : Deque<Token>) : ParseResult<Expression> {
             else
                 Failure("Expecting ')'")
         }
-        is Number -> Success(Num(Integer.parseInt((token as Token).text)!!))
+        is Number -> Success(Num(Integer.parseInt((token as Token).text)))
         else -> Failure("Unexpected EOF")
     }
 }