Allow inferring property type from its getter

#KT-550 Fixed

compiler/testData/diagnostics/tests/properties/inferenceFromGetters/objectExpression.kt

@@ -0,0 +1,35 @@
+// !CHECK_TYPE
+object Outer {
+    private var x
+        get() = object : CharSequence {
+            override val length: Int
+                get() = 0
+
+            override fun get(index: Int): Char {
+                checkSubtype<CharSequence>(<!TYPECHECKER_HAS_RUN_INTO_RECURSIVE_PROBLEM!>x<!>)
+                return ' '
+            }
+
+            override fun subSequence(startIndex: Int, endIndex: Int) = ""
+
+            fun bar() {
+            }
+        }
+        set(q) {
+            checkSubtype<CharSequence>(x)
+            y = q
+            x = q
+        }
+
+    private var y = <!DEBUG_INFO_LEAKING_THIS!>x<!>
+
+    fun foo() {
+        x = y
+
+        checkSubtype<CharSequence>(x)
+        checkSubtype<CharSequence>(y)
+
+        x.bar()
+        y.bar()
+    }
+}