IR: do not assert presence of property getter in IrFakeOverrideBuilder

#KT-65456 Fixed

compiler/testData/codegen/box/sam/fieldInJavaSamInterface.kt

@@ -0,0 +1,24 @@
+// TARGET_BACKEND: JVM
+// SAM_CONVERSIONS: CLASS
+// FILE: S.java
+public interface S {
+    String bar(String t);
+
+    S RESULT = new S() {
+        @Override
+        public String bar(String t) { return t; }
+    };
+}
+
+// FILE: J.java
+public class J {
+    public static String foo(String e, S c) {
+        return c.bar(e);
+    }
+}
+
+// FILE: box.kt
+fun box(): String {
+    val s: (String) -> String = { S.RESULT.bar(it) }
+    return J.foo("OK", S(s))
+}