KT-5524 Support [platformName] annotation for class members

@platformName is now supported for final non-overriding class member functions
(including property accessors).
Front-end provides diagnostics for inapplicable annotation cases.
Code generation updated:
- ignore kotlin.platform.platformName annotation for Java class methods;
- bridges generation generates proper JVM declarations in case of methods renamed with @platformName.
@platformName-related tests added.

#KT-5524 Fixed

compiler/testData/diagnostics/testsWithStdLib/duplicateJvmSignature/platformNames.kt

@@ -4,4 +4,21 @@ import kotlin.platform.*
 @platformName("bar")
 fun foo(a: Any) {}
 
-fun Any.foo() {}
+fun Any.foo() {}
+
+@platformName("barInt")
+fun bar(x: List<Int>) {}
+
+@platformName("barStr")
+fun bar(x: List<String>) {}
+
+class C {
+    var rwProp: Int
+        @platformName("get_rwProp")
+        get() = 0
+        @platformName("set_rwProp")
+        set(v) {}
+
+    fun getRwProp(): Int = 123
+    fun setRwProp(v: Int) {}
+}