Tag experimental API tests

Followup of #19811

Author: nicolasstucki

tests/init-global/pos/global-region1.scala

@@ -1,3 +1,5 @@
+//> using options -experimental -Yno-experimental
+
 import scala.annotation.init.region
 
 trait B { def foo(): Int }

tests/init-global/warn/i18628_3.scala

@@ -1,3 +1,5 @@
+//> using options -experimental -Yno-experimental
+
 import scala.annotation.init.widen
 
 object Test:

tests/neg-macros/i19842/Macro.scala

@@ -1,3 +1,4 @@
+//> using options -experimental -Yno-experimental
 
 import scala.annotation.{experimental, targetName}
 import scala.quoted.*

tests/neg/inline-unstable-accessors.scala

@@ -1,4 +1,4 @@
-//> using options -Werror -WunstableInlineAccessors -explain
+//> using options -experimental -Yno-experimental -Werror -WunstableInlineAccessors -explain
 
 package foo
 import scala.annotation.publicInBinary

tests/neg/publicInBinaryOverride.check

@@ -1,5 +1,5 @@
--- [E164] Declaration Error: tests/neg/publicInBinaryOverride.scala:8:15 -----------------------------------------------
-8 | override def f(): Unit = () // error
- | ^
- | error overriding method f in class A of type (): Unit;
- | method f of type (): Unit also needs to be declared with @publicInBinary
+-- [E164] Declaration Error: tests/neg/publicInBinaryOverride.scala:10:15 ----------------------------------------------
+10 | override def f(): Unit = () // error
+  | ^
+  | error overriding method f in class A of type (): Unit;
+  | method f of type (): Unit also needs to be declared with @publicInBinary

tests/neg/publicInBinaryOverride.scala

@@ -1,3 +1,5 @@
+//> using options -experimental -Yno-experimental
+
 import scala.annotation.publicInBinary
 
 class A:

tests/pos/TupleReverseOnto.scala

@@ -1,4 +1,7 @@
+//> using options -experimental -Yno-experimental
+
 import scala.Tuple.*
+
 def test[T1, T2, T3, T4] =
  summon[ReverseOnto[(T1, T2), (T3, T4)] =:= ReverseOnto[(T1, T2), (T3, T4)]]
  summon[ReverseOnto[(T1, T2), (T3, T4)] =:= (T2, T1, T3, T4)]

tests/pos/i7851.scala

@@ -1,3 +1,5 @@
+//> using options -experimental -Yno-experimental
+
 trait Wrappable[T] { }
 given Wrappable[Float] with { }
 

tests/pos/tupled-function-instances.scala

@@ -1,3 +1,5 @@
+//> using options -experimental -Yno-experimental
+
 import scala.util.TupledFunction
 object Test {
  def main(args: Array[String]): Unit = {

tests/run-deep-subtype/Tuple-reverse.scala

@@ -1,3 +1,5 @@
+//> using options -experimental -Yno-experimental
+
 import scala.reflect.ClassTag
 
 object Test {