FIR: add status line to all failing black box tests

compiler/testData/codegen/box/annotations/genericAnnotations.kt

@@ -1,5 +1,5 @@
 // IGNORE_BACKEND_FIR: JVM_IR
-// See KT-46967
+// FIR status: generic annotation aren't supported in FIR inference yet; see also KT-46967
 // MODULE: lib
 // FILE: l1.kt
 package ann

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

@@ -2,6 +2,7 @@
 // is seen as coming from the same module.
 // See IrSourceCompilerForInline.kt:isCallInsideSameModuleAsCallee.
 // IGNORE_BACKEND_FIR: JVM_IR
+// FIR status: assertion failed: assert(one.javaClass.getEnclosingClass().getName() == "test.C")
 // TARGET_BACKEND: JVM_IR
 // IGNORE_DEXING
 // WITH_STDLIB

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

@@ -1,5 +1,5 @@
-// Multi-platform not supported with FIR yet.
 // IGNORE_BACKEND_FIR: JVM_IR
+// FIR status: expect/actual in the same module (ACTUAL_WITHOUT_EXPECT)
 // IGNORE_BACKEND: JVM
 // IGNORE_BACKEND: WASM
 

compiler/testData/codegen/box/annotations/singleAssignmentToVarargInAnnotation.kt

@@ -1,4 +1,5 @@
 // IGNORE_BACKEND_FIR: JVM_IR
+// FIR status: don't support legacy feature
 // !LANGUAGE: -ProhibitAssigningSingleElementsToVarargsInNamedForm
 // TARGET_BACKEND: JVM