JVM IR: Avoid direct invokes in callable reference tests

Due to the direct invoke optimization, most callable reference tests
were not generating callable references/lambdas.

compiler/testData/codegen/box/functions/invoke/extensionInvokeOnExpr.kt

@@ -13,8 +13,8 @@ fun B.test(): 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()}.let { it() }() != "##") return "fail6"
+    if ({ -> A()}.let { it() }(37) != "#37") return "fail7"
     return "OK"
 }
 

compiler/testData/codegen/box/functions/invoke/invokeOnExprByConvention.kt

@@ -14,7 +14,7 @@ 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()}.let { it() }() != "##") return "fail6"
+    if ({ -> A()}.let { it() }(37) != "#37") return "fail7"
     return "OK"
 }

compiler/testData/codegen/box/functions/kt2481.kt

@@ -9,6 +9,6 @@ public class B(): A(){
     public override fun method() : String {
         return ({
           super.method()
-        })()
+        }).let { it() }
     }
 }

compiler/testData/codegen/box/functions/localFunctions/kt2895.kt

@@ -3,7 +3,7 @@ fun outer() {
         if (i > 0){
             {
                 it: Int -> inner(0) // <- invocation of literal itself is generated instead
-            }.invoke(1)
+            }.let { it.invoke(1) }
         }
     }
     inner(1)

compiler/testData/codegen/box/functions/localFunctions/overloadedLocalFunction3.kt

@@ -14,7 +14,7 @@ fun box(): String {
         {
             foo(foo, 1)
             foo("K")
-        } ()
+        }.let { it() }
     }
 
     return s