FE1.0/FIR: slightly fix diagnostic messages about OptIn

compiler/testData/cli/jvm/optInEmptyMessage.out

@@ -1,4 +1,4 @@
-compiler/testData/cli/jvm/optInEmptyMessage.kt:8:5: error: this declaration needs OptIn. Its usage must be marked with '@EmptyMarker' or '@OptIn(EmptyMarker::class)'
+compiler/testData/cli/jvm/optInEmptyMessage.kt:8:5: error: this declaration needs opt-in. Its usage must be marked with '@EmptyMarker' or '@OptIn(EmptyMarker::class)'
     foo()
     ^
 COMPILATION_ERROR

compiler/testData/cli/jvm/optInEmptyMessageFir.out

@@ -1,7 +1,7 @@
 warning: ATTENTION!
  This build uses in-dev FIR:
   -Xuse-fir
-compiler/testData/cli/jvm/optInEmptyMessageFir.kt:8:5: error: this declaration needs OptIn. Its usage must be marked with '@EmptyMarker' or '@OptIn(EmptyMarker::class)'
+compiler/testData/cli/jvm/optInEmptyMessageFir.kt:8:5: error: this declaration needs opt-in. Its usage must be marked with '@EmptyMarker' or '@OptIn(EmptyMarker::class)'
     foo()
     ^
 COMPILATION_ERROR

compiler/testData/cli/jvm/optInOverrideMessage.out

@@ -1,7 +1,7 @@
-compiler/testData/cli/jvm/optInOverrideMessage.kt:16:18: error: base declaration of supertype 'Base' needs OptIn. This API is experimental and can change at any time, please use with care. The declaration override must be annotated with '@Marker'
+compiler/testData/cli/jvm/optInOverrideMessage.kt:16:18: error: base declaration of supertype 'Base' needs opt-in. This API is experimental and can change at any time, please use with care. The declaration override must be annotated with '@Marker' or '@OptIn(Marker::class)'
     override fun foo() {}
                  ^
-compiler/testData/cli/jvm/optInOverrideMessage.kt:18:18: error: base declaration of supertype 'Base' needs OptIn. The declaration override must be annotated with '@EmptyMarker'
+compiler/testData/cli/jvm/optInOverrideMessage.kt:18:18: error: base declaration of supertype 'Base' needs opt-in. The declaration override must be annotated with '@EmptyMarker' or '@OptIn(EmptyMarker::class)'
     override fun bar() {}
                  ^
 COMPILATION_ERROR

compiler/testData/cli/jvm/optInOverrideMessageFir.out

@@ -1,10 +1,10 @@
 warning: ATTENTION!
  This build uses in-dev FIR:
   -Xuse-fir
-compiler/testData/cli/jvm/optInOverrideMessageFir.kt:16:18: error: base declaration of supertype 'Base' needs OptIn. This API is experimental and can change at any time, please use with care. The declaration override must be annotated with '@Marker'
+compiler/testData/cli/jvm/optInOverrideMessageFir.kt:16:18: error: base declaration of supertype 'Base' needs opt-in. This API is experimental and can change at any time, please use with care. The declaration override must be annotated with '@Marker' or '@OptIn(Marker::class)'
     override fun foo() {}
                  ^
-compiler/testData/cli/jvm/optInOverrideMessageFir.kt:18:18: error: base declaration of supertype 'Base' needs OptIn. The declaration override must be annotated with '@EmptyMarker'
+compiler/testData/cli/jvm/optInOverrideMessageFir.kt:18:18: error: base declaration of supertype 'Base' needs opt-in. The declaration override must be annotated with '@EmptyMarker' or '@OptIn(EmptyMarker::class)'
     override fun bar() {}
                  ^
 COMPILATION_ERROR

compiler/testData/cli/jvm/useDeclarationThatWasExperimentalWithoutMarker2.out

@@ -1,17 +1,17 @@
 warning: language version 1.4 is deprecated and its support will be removed in a future version of Kotlin
-compiler/testData/cli/jvm/useDeclarationThatWasExperimentalWithoutMarker2.kt:2:13: warning: this declaration needs OptIn. Its usage should be marked with '@kotlin.ExperimentalUnsignedTypes' or '@OptIn(kotlin.ExperimentalUnsignedTypes::class)'
+compiler/testData/cli/jvm/useDeclarationThatWasExperimentalWithoutMarker2.kt:2:13: warning: this declaration needs opt-in. Its usage should be marked with '@kotlin.ExperimentalUnsignedTypes' or '@OptIn(kotlin.ExperimentalUnsignedTypes::class)'
 fun test(p: ULong) {
             ^
-compiler/testData/cli/jvm/useDeclarationThatWasExperimentalWithoutMarker2.kt:3:12: warning: this declaration needs OptIn. Its usage should be marked with '@kotlin.ExperimentalUnsignedTypes' or '@OptIn(kotlin.ExperimentalUnsignedTypes::class)'
+compiler/testData/cli/jvm/useDeclarationThatWasExperimentalWithoutMarker2.kt:3:12: warning: this declaration needs opt-in. Its usage should be marked with '@kotlin.ExperimentalUnsignedTypes' or '@OptIn(kotlin.ExperimentalUnsignedTypes::class)'
     val z: ULong = p
            ^
-compiler/testData/cli/jvm/useDeclarationThatWasExperimentalWithoutMarker2.kt:3:20: warning: this declaration needs OptIn. Its usage should be marked with '@kotlin.ExperimentalUnsignedTypes' or '@OptIn(kotlin.ExperimentalUnsignedTypes::class)'
+compiler/testData/cli/jvm/useDeclarationThatWasExperimentalWithoutMarker2.kt:3:20: warning: this declaration needs opt-in. Its usage should be marked with '@kotlin.ExperimentalUnsignedTypes' or '@OptIn(kotlin.ExperimentalUnsignedTypes::class)'
     val z: ULong = p
                    ^
-compiler/testData/cli/jvm/useDeclarationThatWasExperimentalWithoutMarker2.kt:4:5: warning: this declaration needs OptIn. Its usage should be marked with '@kotlin.ExperimentalUnsignedTypes' or '@OptIn(kotlin.ExperimentalUnsignedTypes::class)'
+compiler/testData/cli/jvm/useDeclarationThatWasExperimentalWithoutMarker2.kt:4:5: warning: this declaration needs opt-in. Its usage should be marked with '@kotlin.ExperimentalUnsignedTypes' or '@OptIn(kotlin.ExperimentalUnsignedTypes::class)'
     z.inv()
     ^
-compiler/testData/cli/jvm/useDeclarationThatWasExperimentalWithoutMarker2.kt:4:7: warning: this declaration needs OptIn. Its usage should be marked with '@kotlin.ExperimentalUnsignedTypes' or '@OptIn(kotlin.ExperimentalUnsignedTypes::class)'
+compiler/testData/cli/jvm/useDeclarationThatWasExperimentalWithoutMarker2.kt:4:7: warning: this declaration needs opt-in. Its usage should be marked with '@kotlin.ExperimentalUnsignedTypes' or '@OptIn(kotlin.ExperimentalUnsignedTypes::class)'
     z.inv()
       ^
 OK