KT-11710 "Replace 'if' with elvis operator": incorrect code generated for 'if' expression

#KT-11710 Fixed

idea/testData/intentions/ifNullToElvis/ifStatementPriority.kt

@@ -0,0 +1,6 @@
+// WITH_RUNTIME
+fun test(a: String?, b: String): String {
+    val x = if (true) a else b
+    <caret>if (x == null) throw Exception()
+    return x
+}

idea/testData/intentions/ifNullToElvis/ifStatementPriority.kt.after

@@ -0,0 +1,5 @@
+// WITH_RUNTIME
+fun test(a: String?, b: String): String {
+    val x = (if (true) a else b) ?: throw Exception()
+    return x
+}