[NI] Disable caching of LHS expression types for "+=" operators

New behavior was introduced in ab506c1579 which breaks compilation on IDE module (see test example) for new inference.

 Now we temporarily disable this optimisation. This is temporarily restriction which will be fixed once we'll have the same rules for lambdas completion

 #KT-34889 Open

compiler/testData/diagnostics/tests/functionLiterals/genericFunctionalTypeOnRHSOfPlusAssign.kt

@@ -0,0 +1,11 @@
+// !DIAGNOSTICS: -UNUSED_PARAMETER
+
+fun <T> Iterable<T>.filter(predicate: (T) -> Boolean): List<T> = TODO()
+operator fun <T> Collection<T>.plus(elements: Iterable<T>): List<T> = TODO()
+
+fun stringCollection(): Collection<String> = TODO()
+
+fun <K> test(c: Collection<K>) {
+    var variants = stringCollection()
+    variants += variants.filter { true }
+}

compiler/testData/diagnostics/tests/functionLiterals/genericFunctionalTypeOnRHSOfPlusAssign.txt

@@ -0,0 +1,6 @@
+package
+
+public fun stringCollection(): kotlin.collections.Collection<kotlin.String>
+public fun </*0*/ K> test(/*0*/ c: kotlin.collections.Collection<K>): kotlin.Unit
+public fun </*0*/ T> kotlin.collections.Iterable<T>.filter(/*0*/ predicate: (T) -> kotlin.Boolean): kotlin.collections.List<T>
+public operator fun </*0*/ T> kotlin.collections.Collection<T>.plus(/*0*/ elements: kotlin.collections.Iterable<T>): kotlin.collections.List<T>