Add "Suspicious collection reassignment" inspection #KT-20626 Fixed

idea/testData/inspectionsLocal/suspiciousCollectionReassignment/mutableMap.kt

@@ -0,0 +1,7 @@
+// PROBLEM: none
+// ERROR: Assignment operators ambiguity: <br>public operator fun <K, V> Map<out Int, Int>.plus(pair: Pair<Int, Int>): Map<Int, Int> defined in kotlin.collections<br>@InlineOnly public inline operator fun <K, V> MutableMap<in Int, in Int>.plusAssign(pair: Pair<Int, Int>): Unit defined in kotlin.collections
+// WITH_RUNTIME
+fun test() {
+    var map = mutableMapOf(1 to 2)
+    map <caret>+= 3 to 4
+}