IR: drop IrFile.fileAnnotations (it already has annotations anyway)

compiler/testData/ir/irText/declarations/annotations/fileAnnotations.txt

@@ -1,6 +1,4 @@
 FILE fqName:test fileName:/fileAnnotations.kt
-  fileAnnotations:
-    @test.A(x = "File annotation")
   annotations:
     CALL 'CONSTRUCTOR visibility:public <> (x:kotlin.String) returnType:test.A flags:[primary]' type=test.A origin=null
       x: CONST String type=kotlin.String value="File annotation"

compiler/testData/ir/irText/declarations/fileWithAnnotations.txt

@@ -1,6 +1,4 @@
 FILE fqName:<root> fileName:/fileWithAnnotations.kt
-  fileAnnotations:
-    @kotlin.jvm.JvmName(name = "FileWithAnnotations")
   annotations:
     CALL 'CONSTRUCTOR IR_EXTERNAL_DECLARATION_STUB visibility:public <> (name:kotlin.String) returnType:kotlin.jvm.JvmName flags:[primary]' type=kotlin.jvm.JvmName origin=null
       name: CONST String type=kotlin.String value="FileWithAnnotations"