Add capture checking to various scala.* base package files

Just imports

Author: natsukagami

library/src/scala/CanEqual.scala

@@ -1,5 +1,7 @@
 package scala
 
+import language.experimental.captureChecking
+
 import annotation.implicitNotFound
 import scala.collection.{Seq, Set, Map}
 

library/src/scala/CanThrow.scala

@@ -2,6 +2,8 @@ package scala
 import language.experimental.erasedDefinitions
 import annotation.{implicitNotFound, experimental, capability}
 
+import language.experimental.captureChecking
+
 /** A capability class that allows to throw exception `E`. When used with the
  *  experimental.saferExceptions feature, a `throw Ex()` expression will require
  *  a given of class `CanThrow[Ex]` to be available.

library/src/scala/Conversion.scala

@@ -1,5 +1,7 @@
 package scala
 
+import language.experimental.captureChecking
+
 /** A class for implicit values that can serve as implicit conversions.
 *  The implicit resolution algorithm will act as if there existed
 *  the additional implicit definition:

library/src/scala/NamedTuple.scala

@@ -1,6 +1,8 @@
 package scala
 import compiletime.ops.boolean.*
 
+import language.experimental.captureChecking
+
 object NamedTuple:
 
   /** The type to which named tuples get mapped to. For instance,

library/src/scala/PolyFunction.scala

@@ -1,5 +1,7 @@
 package scala
 
+import language.experimental.captureChecking
+
 /* (EXPERIMENTAL) NEW DOCUMENTATION: This should be used when we stabilize erased definitions or other generalize other function types.
  *
  * Marker trait for many (poly) function types.

library/src/scala/Precise.scala

@@ -1,4 +1,7 @@
 package scala
+
+import language.experimental.captureChecking
+
 import annotation.experimental
 import language.experimental.erasedDefinitions
 

library/src/scala/Selectable.scala

@@ -1,5 +1,6 @@
 package scala
 
+import language.experimental.captureChecking
 
 /** A marker trait for objects that support structural selection via
  *  `selectDynamic` and `applyDynamic`

library/src/scala/caps/Pure.scala

@@ -1,6 +1,8 @@
 package scala
 package caps
 
+import language.experimental.captureChecking
+
 /** A marker trait that declares that all inheriting classes are "pure" in the
  *  sense that their values retain no capabilities including capabilities needed
  *  to perform effects. This has formal meaning only under capture checking.

library/src/scala/main.scala

@@ -8,6 +8,8 @@
 
 package scala
 
+import language.experimental.captureChecking
+
 /** An annotation that designates a main function
  */
 class main extends scala.annotation.Annotation {}

library/src/scala/runtime/stdLibPatches/Predef.scala

@@ -1,5 +1,7 @@
 package scala.runtime.stdLibPatches
 
+import scala.language.experimental.captureChecking
+
 import scala.annotation.experimental
 import scala.annotation.internal.RuntimeChecked