Dealing with infix calls in completion

#KT-4846 Fixed

idea/testData/completion/basic/multifile/NotImportedInfixExtension/NotImportedInfixExtension.dependency.kt

@@ -0,0 +1,10 @@
+package other
+
+import pack.C
+
+fun C.xxx() {}
+fun C.yyy(p: Int) {}
+fun C.zzz(p1: Int, p2: Int) {}
+val C.extensionProp: Int get() = 1
+
+// ALLOW_AST_ACCESS

idea/testData/completion/basic/multifile/NotImportedInfixExtension/NotImportedInfixExtension.kt

@@ -0,0 +1,13 @@
+package pack
+
+class C
+
+fun f() {
+    C() <caret>
+}
+
+// INVOCATION_COUNT: 2
+// ABSENT: "xxx"
+// EXIST: "yyy"
+// ABSENT: "zzz"
+// ABSENT: "extensionProp"