KT-52791 Make it possible to pass multiple context receivers to a class

compiler/testData/codegen/box/extensionClasses/multiple.kt

@@ -0,0 +1,19 @@
+// !LANGUAGE: +ContextReceivers
+// TARGET_BACKEND: JVM_IR
+
+class A(val a: String)
+class B(val b: String)
+
+context(A, B)
+class C {
+    fun foo() = this@A.a + this@B.b
+}
+
+fun box(): String {
+    val c = with(A("O")) {
+        with(B("K")) {
+            C()
+        }
+    }
+    return c.foo()
+}