Avoid non-null assertions for inline classes based on nullable types

Note that there are more places where assertions for inline classes should refined:
  - lateinit vars
  - values that come from Java
  - type casts (interfaces to inline class type)

compiler/testData/codegen/box/inlineClasses/noAssertionsOnInlineClassBasedOnNullableType.kt

@@ -0,0 +1,38 @@
+// !LANGUAGE: +InlineClasses
+
+inline class Result<T>(val a: Any?)
+
+fun resultOfIntToResultOfInt(r: Result<Int>): Result<Int> {
+    return r
+}
+
+fun <T> idResult(r: Result<T>): Result<T> = r
+
+fun Result<Int>.extension(): Result<Int> = this
+
+fun box(): String {
+    val r = Result<Int>(null)
+
+    resultOfIntToResultOfInt(r)
+    resultOfIntToResultOfInt(Result<Int>(null))
+
+    val nonNull1 = resultOfIntToResultOfInt(r)
+    val nonNull2 = resultOfIntToResultOfInt(Result<Int>(null))
+
+    resultOfIntToResultOfInt(nonNull1)
+
+    if (nonNull1.a != null) return "fail"
+    if (nonNull2.a != null) return "fail"
+
+    if (resultOfIntToResultOfInt(r).a != null) return "fail"
+
+    idResult(Result<String>(null))
+
+    val id = idResult(r)
+    if (id.a != null) return "fail"
+
+    r.extension()
+    Result<Int>(null).extension()
+
+    return "OK"
+}