Support platformStatic for properties

#KT-5766 Fixed

compiler/testData/codegen/boxWithStdlib/platformStatic/simple.kt

@@ -4,6 +4,8 @@ object A {
 
     val b: String = "OK"
 
+    platformStatic val c: String = "OK"
+
     platformStatic fun test1() : String {
         return b
     }
@@ -36,5 +38,7 @@ fun box(): String {
 
     if (with(A) {"1".test5()} != "1OK") return "fail 5"
 
+    if (A.c != "OK") return "fail 6"
+
     return "OK"
 }