JVM, JVM_IR: no nullability annotations on private and synthetic methods

NB it looks like it doesn't cover all cases, e.g., some synthetic
methods generated for suspend functions.

plugins/kapt3/kapt3-compiler/testData/kotlinRunner/DefaultParameterValues.it.txt

@@ -23,7 +23,6 @@ import java.lang.System;
 @kotlin.Metadata()
 @Anno()
 public final class User {
-    @org.jetbrains.annotations.NotNull()
     private final java.lang.String name = "John";
 
     @org.jetbrains.annotations.NotNull()

plugins/kapt3/kapt3-compiler/testData/kotlinRunner/Overloads.it.txt

@@ -25,7 +25,6 @@ import java.lang.System;
 public final class State {
     private final int someInt = 0;
     private final long someLong = 0L;
-    @org.jetbrains.annotations.NotNull()
     private final java.lang.String someString = null;
 
     public final int getSomeInt() {