Initial support for KT-7090 Completion for callable references

#KT-7090 Fixed

idea/idea-completion/testData/handlers/basic/callableReference/ClassConstructor.kt

@@ -0,0 +1,11 @@
+package ppp
+
+class X(p: Int)
+
+class C {
+    fun foo() {
+        val v = ::<caret>
+    }
+}
+
+// ELEMENT: X

idea/idea-completion/testData/handlers/basic/callableReference/ClassConstructor.kt.after

@@ -0,0 +1,11 @@
+package ppp
+
+class X(p: Int)
+
+class C {
+    fun foo() {
+        val v = ::X<caret>
+    }
+}
+
+// ELEMENT: X

idea/idea-completion/testData/handlers/basic/callableReference/EmptyQualifier.kt

@@ -0,0 +1,9 @@
+fun globalFun(p: Int) {}
+
+class C {
+    fun foo() {
+        val v = ::<caret>
+    }
+}
+
+// ELEMENT: globalFun

idea/idea-completion/testData/handlers/basic/callableReference/EmptyQualifier.kt.after

@@ -0,0 +1,9 @@
+fun globalFun(p: Int) {}
+
+class C {
+    fun foo() {
+        val v = ::globalFun<caret>
+    }
+}
+
+// ELEMENT: globalFun

idea/idea-completion/testData/handlers/basic/callableReference/NonEmptyQualifier.kt

@@ -0,0 +1,11 @@
+class C {
+    fun foo() {
+        val v = D::<caret>
+    }
+}
+
+class D {
+    fun memberFun(s: String){}
+}
+
+// ELEMENT: memberFun

idea/idea-completion/testData/handlers/basic/callableReference/NonEmptyQualifier.kt.after

@@ -0,0 +1,11 @@
+class C {
+    fun foo() {
+        val v = D::memberFun<caret>
+    }
+}
+
+class D {
+    fun memberFun(s: String){}
+}
+
+// ELEMENT: memberFun

idea/idea-completion/testData/handlers/basic/callableReference/Property.kt

@@ -0,0 +1,9 @@
+class C {
+    val prop: Int = 0
+
+    fun foo() {
+        val v = ::<caret>
+    }
+}
+
+// ELEMENT: prop

idea/idea-completion/testData/handlers/basic/callableReference/Property.kt.after

@@ -0,0 +1,9 @@
+class C {
+    val prop: Int = 0
+
+    fun foo() {
+        val v = ::prop<caret>
+    }
+}
+
+// ELEMENT: prop