expect/actual classes: experimental -> Beta

KT-61573
^KT-61712 Fixed
Review: https://jetbrains.team/p/kt/reviews/12044/files

It's a follow up commit

According our guidelines, it must be in Beta
https://kotlinlang.org/docs/components-stability.html#stability-of-subcomponents

And the whole multiplatform was in Beta, so we can't make part of the
multiplatform to have lower stability level

compiler/testData/cli/js/jsExtraHelp.out

@@ -87,7 +87,7 @@ where advanced options include:
                              The corresponding calls' declarations may not be marked with @BuilderInference.
   -Xklib-enable-signature-clash-checks
                              Enable the checks on uniqueness of signatures
-  -Xexpect-actual-classes    The expect/actual classes (including interfaces, objects, annotations, enums, actual typealiases) are an experimental feature.
+  -Xexpect-actual-classes    'expect'/'actual' classes (including interfaces, objects, annotations, enums, and 'actual' typealiases) are in Beta.
                              Kotlin reports a warning every time you use them. You can use this flag to mute the warning.
   -Xexpect-actual-linker     Enable experimental expect/actual linker
   -Xexplicit-api={strict|warning|disable}

compiler/testData/cli/jvm/extraHelp.out

@@ -178,7 +178,7 @@ where advanced options include:
                              The corresponding calls' declarations may not be marked with @BuilderInference.
   -Xklib-enable-signature-clash-checks
                              Enable the checks on uniqueness of signatures
-  -Xexpect-actual-classes    The expect/actual classes (including interfaces, objects, annotations, enums, actual typealiases) are an experimental feature.
+  -Xexpect-actual-classes    'expect'/'actual' classes (including interfaces, objects, annotations, enums, and 'actual' typealiases) are in Beta.
                              Kotlin reports a warning every time you use them. You can use this flag to mute the warning.
   -Xexpect-actual-linker     Enable experimental expect/actual linker
   -Xexplicit-api={strict|warning|disable}

compiler/testData/cli/jvm/firMultiplatformCompilationWithPsiWithoutErrors.out

@@ -9,10 +9,10 @@ as no stability/compatibility guarantees are given on
 compiler or generated code. Use it at your own risk!
 
 warning: language version 2.0 is experimental, there are no backwards compatibility guarantees for new language and library features
-compiler/testData/cli/jvm/firMultiplatformCompilationWithoutErrors/common.kt:1:1: warning: the expect/actual classes (including interfaces, objects, annotations, enums, actual typealiases) are an experimental feature. You can use -Xexpect-actual-classes flag to suppress this warning.
+compiler/testData/cli/jvm/firMultiplatformCompilationWithoutErrors/common.kt:1:1: warning: 'expect'/'actual' classes (including interfaces, objects, annotations, enums, and 'actual' typealiases) are in Beta. You can use -Xexpect-actual-classes flag to suppress this warning. Also see: https://youtrack.jetbrains.com/issue/KT-61573
 expect interface A {
 ^
-compiler/testData/cli/jvm/firMultiplatformCompilationWithoutErrors/jvm.kt:1:1: warning: the expect/actual classes (including interfaces, objects, annotations, enums, actual typealiases) are an experimental feature. You can use -Xexpect-actual-classes flag to suppress this warning.
+compiler/testData/cli/jvm/firMultiplatformCompilationWithoutErrors/jvm.kt:1:1: warning: 'expect'/'actual' classes (including interfaces, objects, annotations, enums, and 'actual' typealiases) are in Beta. You can use -Xexpect-actual-classes flag to suppress this warning. Also see: https://youtrack.jetbrains.com/issue/KT-61573
 actual interface A {
 ^
 OK

compiler/testData/cli/jvm/firMultiplatformCompilationWithoutErrors.out

@@ -9,10 +9,10 @@ as no stability/compatibility guarantees are given on
 compiler or generated code. Use it at your own risk!
 
 warning: language version 2.0 is experimental, there are no backwards compatibility guarantees for new language and library features
-compiler/testData/cli/jvm/firMultiplatformCompilationWithoutErrors/common.kt:1:1: warning: the expect/actual classes (including interfaces, objects, annotations, enums, actual typealiases) are an experimental feature. You can use -Xexpect-actual-classes flag to suppress this warning.
+compiler/testData/cli/jvm/firMultiplatformCompilationWithoutErrors/common.kt:1:1: warning: 'expect'/'actual' classes (including interfaces, objects, annotations, enums, and 'actual' typealiases) are in Beta. You can use -Xexpect-actual-classes flag to suppress this warning. Also see: https://youtrack.jetbrains.com/issue/KT-61573
 expect interface A {
 ^
-compiler/testData/cli/jvm/firMultiplatformCompilationWithoutErrors/jvm.kt:1:1: warning: the expect/actual classes (including interfaces, objects, annotations, enums, actual typealiases) are an experimental feature. You can use -Xexpect-actual-classes flag to suppress this warning.
+compiler/testData/cli/jvm/firMultiplatformCompilationWithoutErrors/jvm.kt:1:1: warning: 'expect'/'actual' classes (including interfaces, objects, annotations, enums, and 'actual' typealiases) are in Beta. You can use -Xexpect-actual-classes flag to suppress this warning. Also see: https://youtrack.jetbrains.com/issue/KT-61573
 actual interface A {
 ^
 OK

compiler/testData/cli/jvm/hmpp/lowLanguageVersion.out

@@ -8,16 +8,16 @@ as no stability/compatibility guarantees are given on
 compiler or generated code. Use it at your own risk!
 
 warning: -Xfragments flag is not supported for language version < 2.0
-compiler/testData/cli/jvm/hmpp/src/a.kt:1:1: warning: the expect/actual classes (including interfaces, objects, annotations, enums, actual typealiases) are an experimental feature. You can use -Xexpect-actual-classes flag to suppress this warning.
+compiler/testData/cli/jvm/hmpp/src/a.kt:1:1: warning: 'expect'/'actual' classes (including interfaces, objects, annotations, enums, and 'actual' typealiases) are in Beta. You can use -Xexpect-actual-classes flag to suppress this warning. Also see: https://youtrack.jetbrains.com/issue/KT-61573
 expect class A {
 ^
-compiler/testData/cli/jvm/hmpp/src/a.kt:5:1: warning: the expect/actual classes (including interfaces, objects, annotations, enums, actual typealiases) are an experimental feature. You can use -Xexpect-actual-classes flag to suppress this warning.
+compiler/testData/cli/jvm/hmpp/src/a.kt:5:1: warning: 'expect'/'actual' classes (including interfaces, objects, annotations, enums, and 'actual' typealiases) are in Beta. You can use -Xexpect-actual-classes flag to suppress this warning. Also see: https://youtrack.jetbrains.com/issue/KT-61573
 expect class B {
 ^
-compiler/testData/cli/jvm/hmpp/src/b.kt:1:1: warning: the expect/actual classes (including interfaces, objects, annotations, enums, actual typealiases) are an experimental feature. You can use -Xexpect-actual-classes flag to suppress this warning.
+compiler/testData/cli/jvm/hmpp/src/b.kt:1:1: warning: 'expect'/'actual' classes (including interfaces, objects, annotations, enums, and 'actual' typealiases) are in Beta. You can use -Xexpect-actual-classes flag to suppress this warning. Also see: https://youtrack.jetbrains.com/issue/KT-61573
 actual class A {
 ^
-compiler/testData/cli/jvm/hmpp/src/c.kt:1:1: warning: the expect/actual classes (including interfaces, objects, annotations, enums, actual typealiases) are an experimental feature. You can use -Xexpect-actual-classes flag to suppress this warning.
+compiler/testData/cli/jvm/hmpp/src/c.kt:1:1: warning: 'expect'/'actual' classes (including interfaces, objects, annotations, enums, and 'actual' typealiases) are in Beta. You can use -Xexpect-actual-classes flag to suppress this warning. Also see: https://youtrack.jetbrains.com/issue/KT-61573
 actual class B {
 ^
 OK

compiler/testData/cli/jvm/hmpp/successfulCompilation.out

@@ -8,16 +8,16 @@ as no stability/compatibility guarantees are given on
 compiler or generated code. Use it at your own risk!
 
 warning: language version 2.0 is experimental, there are no backwards compatibility guarantees for new language and library features
-compiler/testData/cli/jvm/hmpp/src/a.kt:1:1: warning: the expect/actual classes (including interfaces, objects, annotations, enums, actual typealiases) are an experimental feature. You can use -Xexpect-actual-classes flag to suppress this warning.
+compiler/testData/cli/jvm/hmpp/src/a.kt:1:1: warning: 'expect'/'actual' classes (including interfaces, objects, annotations, enums, and 'actual' typealiases) are in Beta. You can use -Xexpect-actual-classes flag to suppress this warning. Also see: https://youtrack.jetbrains.com/issue/KT-61573
 expect class A {
 ^
-compiler/testData/cli/jvm/hmpp/src/a.kt:5:1: warning: the expect/actual classes (including interfaces, objects, annotations, enums, actual typealiases) are an experimental feature. You can use -Xexpect-actual-classes flag to suppress this warning.
+compiler/testData/cli/jvm/hmpp/src/a.kt:5:1: warning: 'expect'/'actual' classes (including interfaces, objects, annotations, enums, and 'actual' typealiases) are in Beta. You can use -Xexpect-actual-classes flag to suppress this warning. Also see: https://youtrack.jetbrains.com/issue/KT-61573
 expect class B {
 ^
-compiler/testData/cli/jvm/hmpp/src/b.kt:1:1: warning: the expect/actual classes (including interfaces, objects, annotations, enums, actual typealiases) are an experimental feature. You can use -Xexpect-actual-classes flag to suppress this warning.
+compiler/testData/cli/jvm/hmpp/src/b.kt:1:1: warning: 'expect'/'actual' classes (including interfaces, objects, annotations, enums, and 'actual' typealiases) are in Beta. You can use -Xexpect-actual-classes flag to suppress this warning. Also see: https://youtrack.jetbrains.com/issue/KT-61573
 actual class A {
 ^
-compiler/testData/cli/jvm/hmpp/src/c.kt:1:1: warning: the expect/actual classes (including interfaces, objects, annotations, enums, actual typealiases) are an experimental feature. You can use -Xexpect-actual-classes flag to suppress this warning.
+compiler/testData/cli/jvm/hmpp/src/c.kt:1:1: warning: 'expect'/'actual' classes (including interfaces, objects, annotations, enums, and 'actual' typealiases) are in Beta. You can use -Xexpect-actual-classes flag to suppress this warning. Also see: https://youtrack.jetbrains.com/issue/KT-61573
 actual class B {
 ^
 OK

compiler/testData/cli/jvm/hmpp/successfulCompilation2.out

@@ -8,16 +8,16 @@ as no stability/compatibility guarantees are given on
 compiler or generated code. Use it at your own risk!
 
 warning: language version 2.0 is experimental, there are no backwards compatibility guarantees for new language and library features
-compiler/testData/cli/jvm/hmpp/src/a.kt:1:1: warning: the expect/actual classes (including interfaces, objects, annotations, enums, actual typealiases) are an experimental feature. You can use -Xexpect-actual-classes flag to suppress this warning.
+compiler/testData/cli/jvm/hmpp/src/a.kt:1:1: warning: 'expect'/'actual' classes (including interfaces, objects, annotations, enums, and 'actual' typealiases) are in Beta. You can use -Xexpect-actual-classes flag to suppress this warning. Also see: https://youtrack.jetbrains.com/issue/KT-61573
 expect class A {
 ^
-compiler/testData/cli/jvm/hmpp/src/a.kt:5:1: warning: the expect/actual classes (including interfaces, objects, annotations, enums, actual typealiases) are an experimental feature. You can use -Xexpect-actual-classes flag to suppress this warning.
+compiler/testData/cli/jvm/hmpp/src/a.kt:5:1: warning: 'expect'/'actual' classes (including interfaces, objects, annotations, enums, and 'actual' typealiases) are in Beta. You can use -Xexpect-actual-classes flag to suppress this warning. Also see: https://youtrack.jetbrains.com/issue/KT-61573
 expect class B {
 ^
-compiler/testData/cli/jvm/hmpp/src/b.kt:1:1: warning: the expect/actual classes (including interfaces, objects, annotations, enums, actual typealiases) are an experimental feature. You can use -Xexpect-actual-classes flag to suppress this warning.
+compiler/testData/cli/jvm/hmpp/src/b.kt:1:1: warning: 'expect'/'actual' classes (including interfaces, objects, annotations, enums, and 'actual' typealiases) are in Beta. You can use -Xexpect-actual-classes flag to suppress this warning. Also see: https://youtrack.jetbrains.com/issue/KT-61573
 actual class A {
 ^
-compiler/testData/cli/jvm/hmpp/src/c.kt:1:1: warning: the expect/actual classes (including interfaces, objects, annotations, enums, actual typealiases) are an experimental feature. You can use -Xexpect-actual-classes flag to suppress this warning.
+compiler/testData/cli/jvm/hmpp/src/c.kt:1:1: warning: 'expect'/'actual' classes (including interfaces, objects, annotations, enums, and 'actual' typealiases) are in Beta. You can use -Xexpect-actual-classes flag to suppress this warning. Also see: https://youtrack.jetbrains.com/issue/KT-61573
 actual class B {
 ^
 OK

compiler/testData/cli/jvm/k2SimpleMultiplatformGenericClass.out

@@ -1,8 +1,8 @@
 warning: language version 2.0 is experimental, there are no backwards compatibility guarantees for new language and library features
-compiler/testData/cli/jvm/k2SimpleMultiplatformGenericClass/common.kt:1:1: warning: the expect/actual classes (including interfaces, objects, annotations, enums, actual typealiases) are an experimental feature. You can use -Xexpect-actual-classes flag to suppress this warning.
+compiler/testData/cli/jvm/k2SimpleMultiplatformGenericClass/common.kt:1:1: warning: 'expect'/'actual' classes (including interfaces, objects, annotations, enums, and 'actual' typealiases) are in Beta. You can use -Xexpect-actual-classes flag to suppress this warning. Also see: https://youtrack.jetbrains.com/issue/KT-61573
 expect class AtomicRef<T> {
 ^
-compiler/testData/cli/jvm/k2SimpleMultiplatformGenericClass/jvm.kt:1:1: warning: the expect/actual classes (including interfaces, objects, annotations, enums, actual typealiases) are an experimental feature. You can use -Xexpect-actual-classes flag to suppress this warning.
+compiler/testData/cli/jvm/k2SimpleMultiplatformGenericClass/jvm.kt:1:1: warning: 'expect'/'actual' classes (including interfaces, objects, annotations, enums, and 'actual' typealiases) are in Beta. You can use -Xexpect-actual-classes flag to suppress this warning. Also see: https://youtrack.jetbrains.com/issue/KT-61573
 actual class AtomicRef<T> constructor(value: T) {
 ^
 OK

compiler/testData/cli/metadata/optionalExpectationUsage.out

@@ -1,4 +1,4 @@
-compiler/testData/cli/metadata/optionalExpectationUsage.kt:3:1: warning: the expect/actual classes (including interfaces, objects, annotations, enums, actual typealiases) are an experimental feature. You can use -Xexpect-actual-classes flag to suppress this warning.
+compiler/testData/cli/metadata/optionalExpectationUsage.kt:3:1: warning: 'expect'/'actual' classes (including interfaces, objects, annotations, enums, and 'actual' typealiases) are in Beta. You can use -Xexpect-actual-classes flag to suppress this warning. Also see: https://youtrack.jetbrains.com/issue/KT-61573
 expect annotation class Ann()
 ^
 OK