[FIR] Allow annotation instantiation.

This commit disables the frontend error reporting for supported cases.

compiler/testData/codegen/box/annotations/instances/kotlinExistingAnnotation.kt

@@ -1,4 +1,3 @@
-// IGNORE_BACKEND_FIR: JVM_IR
 // TARGET_BACKEND: JVM_IR
 
 // WITH_RUNTIME
@@ -20,4 +19,4 @@ fun box(): String {
     if (m.toString() == """@kotlin.Metadata(bytecodeVersion=[1, 0, 3], data1=[], data2=[], extraInt=0, extraString=, kind=0, metadataVersion=[], packageName=foo)""")
         return "OK"
     return m.toString()
-}
+}