Fix tests: "infix modifier required" and "operator modifier required" errors

compiler/testData/codegen/boxWithStdlib/reflection/properties/getExtensionPropertiesMutableVsReadonly.kt

@@ -20,7 +20,7 @@ fun box(): String {
 
     val a = A()
     mutable as KMutableProperty2<A, String, String>
-    assert(mutable[a, ""] == "before") { "Fail 3: ${mutable.get(a, "")}" }
-    mutable[a, ""] = "OK"
+    assert(mutable.get(a, "") == "before") { "Fail 3: ${mutable.get(a, "")}" }
+    mutable.set(a, "", "OK")
     return mutable.get(a, "")
 }

compiler/testData/codegen/boxWithStdlib/reflection/properties/getPropertiesMutableVsReadonly.kt

@@ -13,7 +13,7 @@ fun box(): String {
 
     val a = A("")
     mutable as KMutableProperty1<A, String>
-    assert(mutable[a] == "before") { "Fail 3: ${mutable.get(a)}" }
-    mutable[a] = "OK"
+    assert(mutable.get(a) == "before") { "Fail 3: ${mutable.get(a)}" }
+    mutable.set(a, "OK")
     return mutable.get(a)
 }

compiler/testData/codegen/boxWithStdlib/reflection/properties/memberAndMemberExtensionWithSameName.kt

@@ -9,14 +9,14 @@ fun box(): String {
     run {
         val foo: KProperty1<A, *> = javaClass<A>().kotlin.memberProperties.single()
         assert(foo.name == "foo") { "Fail name: $foo (${foo.name})" }
-        assert(foo.get(A()) == "member") { "Fail value: ${foo[A()]}" }
+        assert(foo.get(A()) == "member") { "Fail value: ${foo.get(A())}" }
     }
 
     run {
         val foo: KProperty2<A, *, *> = javaClass<A>().kotlin.memberExtensionProperties.single()
         assert(foo.name == "foo") { "Fail name: $foo (${foo.name})" }
         foo as KProperty2<A, Unit, *>
-        assert(foo.get(A(), Unit) == "extension") { "Fail value: ${foo[A(), Unit]}" }
+        assert(foo.get(A(), Unit) == "extension") { "Fail value: ${foo.get(A(), Unit)}" }
     }
 
     return "OK"

compiler/testData/codegen/boxWithStdlib/reflection/properties/privatePlatformStaticVarInObject.kt

@@ -11,15 +11,15 @@ fun box(): String {
     p.isAccessible = true
 
     try {
-        p[null] = "OK"
+        p.set(null, "OK")
         return "Fail: set should check that first argument is Obj"
     } catch (e: IllegalArgumentException) {}
 
     try {
-        p[null]
+        p.get(null)
         return "Fail: get should check that first argument is Obj"
     } catch (e: IllegalArgumentException) {}
 
-    p[Obj] = "OK"
-    return p[Obj]
+    p.set(Obj, "OK")
+    return p.get(Obj)
 }

compiler/testData/codegen/boxWithStdlib/reflection/properties/protectedClassVar.kt

@@ -25,5 +25,5 @@ fun box(): String {
 
     f.set(a, ":)")
 
-    return if (f[a] != ":)") "Fail: ${f[a]}" else "OK"
+    return if (f.get(a) != ":)") "Fail: ${f.get(a)}" else "OK"
 }