Regression: correct smart cast from Type? to Type!

compiler/testData/diagnostics/tests/smartCasts/varnotnull/toFlexibleType.kt

@@ -0,0 +1,16 @@
+// FILE: J.java
+
+class J {
+    static String foo() { return "abc"; }
+}
+
+// FILE: test.kt
+
+fun bar() {
+    var v: String?
+    v = J.foo()
+    <!DEBUG_INFO_SMARTCAST!>v<!>.length
+    gav(<!DEBUG_INFO_SMARTCAST!>v<!>)
+}
+
+fun gav(v: String) = v

compiler/testData/diagnostics/tests/smartCasts/varnotnull/toFlexibleType.txt

@@ -0,0 +1,14 @@
+package
+
+public fun bar(): kotlin.Unit
+public fun gav(/*0*/ v: kotlin.String): kotlin.String
+
+public/*package*/ open class J {
+    public/*package*/ constructor J()
+    public open override /*1*/ /*fake_override*/ fun equals(/*0*/ other: kotlin.Any?): kotlin.Boolean
+    public open override /*1*/ /*fake_override*/ fun hashCode(): kotlin.Int
+    public open override /*1*/ /*fake_override*/ fun toString(): kotlin.String
+
+    // Static members
+    public/*package*/ open fun foo(): kotlin.String!
+}