Report JVM signature clashes from JVM_IR

Also:

* Do not rename public ABI fields
This includes backing fields for const, lateinit, @JvmField properties,
and instance fields for objects.

* FAKE_OVERRIDE declarations for static members of parent Java classes
Required to report cases when a Kotlin function accidentally overrides
Java class member.

compiler/testData/diagnostics/testsWithJvmBackend/duplicateJvmSignature/specialNames/instance_ir.kt

@@ -0,0 +1,9 @@
+// TARGET_BACKEND: JVM_IR
+
+object O {
+    val INSTANCE: O = null!!
+}
+
+<!CONFLICTING_JVM_DECLARATIONS!>object O2<!> {
+    <!CONFLICTING_JVM_DECLARATIONS!>lateinit var INSTANCE: O2<!>
+}