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/bytecodeText/when/exhaustiveWhenSpecialCases.kt

@@ -81,7 +81,7 @@ fun testLambdaResultExpression_throws(a: A) {
             A.V1 -> 1
             // else -> throw
         }
-    }()
+    }.let { it() }
 }
 
 // JVM_TEMPLATES