Add MultiFileHighlightingTest which checks that other files are not parsed during highlighting

idea/testData/multiFileHighlighting/dependencies/delegates.kt

@@ -0,0 +1,12 @@
+package delegates
+
+import util.*
+
+class D(val t: T, val t2: T2): T by t, T2 by t2 {
+    fun anotherFun() {
+    }
+}
+
+class WithDelegatedProperty() {
+    val i: Int by someInvalidCode
+}

idea/testData/multiFileHighlighting/dependencies/enums.kt

@@ -0,0 +1,18 @@
+package enums
+
+trait Base {
+    fun f() {
+    }
+}
+
+enum class E(val i: Int = 0): Base {
+    E1: E() {
+        override fun f() {
+        }
+    }
+    E2: E(3) {
+        override fun f() {
+        }
+    }
+    E3
+}

idea/testData/multiFileHighlighting/dependencies/util.kt

@@ -0,0 +1,49 @@
+public package util
+
+trait T {
+    fun f()
+}
+
+trait T2 {
+    fun g() {
+    }
+}
+
+suppress("UNRESOLVED_REFERENCE")
+class Invalid: I
+
+class A(val i: Int)
+
+suppress("FINAL_SUPERTYPE")
+class B: A(1) {
+}
+
+open class C(val s: String, i: Int): A(i), T {
+    override fun f() {}
+}
+
+fun topLevelFun(u: A): A {
+    return A(u.i)
+}
+
+val topLevelVal: A = C("", 0)
+var topLevelVar: A = B()
+
+object topLevelObject: T {
+    override fun f() {
+
+    }
+
+    fun g() {
+    }
+}
+
+fun funWithUnspecifiedType() = 3
+
+fun funWithVararg(vararg i: Int): IntArray {
+    return i
+}
+
+fun <T, G> funWithWhere(a: G, b: T) where T: Collection<G> {
+
+}