Optimization to reuse BindingContext in completion

idea/idea-completion/testData/incrementalResolve/dataFlowInfoFromSameStatement.kt

@@ -0,0 +1,10 @@
+fun foo(p: Any): String {
+    println(1)
+    if (<before><change>
+}
+
+fun bar(s: String): Boolean = true
+
+// TYPE: "p is String && bar("
+// COMPLETION_TYPE: SMART
+// EXIST: p