Migrate testdata to new lambda syntax

js/js.translator/testData/expression/invoke/cases/explicitInvokeLambda.kt

@@ -1,6 +1,6 @@
 package foo
 
 fun box(): String {
-    var foo = {(x: String) -> x + "K" }
+    var foo = { x: String -> x + "K" }
     return foo.invoke("O")
 }

js/js.translator/testData/expression/invoke/cases/invokeInFunctionLiteral.kt

@@ -1,9 +1,9 @@
 package foo
 
 fun box(): Boolean {
-    val v1 = {(x: Int) -> x}(2)
+    val v1 = { x: Int -> x}(2)
 
-    val f = {(x: Int) -> x}
+    val f = { x: Int -> x}
     val v2 = (f)(2)
 
     return v1 == 2 && v2 == 2

js/js.translator/testData/expression/invoke/cases/invokeOnExprByConvention.kt

@@ -13,7 +13,7 @@ fun box(): String {
     if (foo()() != "##") return "fail3"
     if (foo()(42) != "#42") return "fail4"
     if ((foo())(42) != "#42") return "fail5"
-    if ({() -> A()}()() != "##") return "fail6"
-    if ({() -> A()}()(37) != "#37") return "fail7"
+    if ({ -> A()}()() != "##") return "fail6"
+    if ({ -> A()}()(37) != "#37") return "fail7"
     return "OK"
 }