Drop "Global capability will not be tracked" warning

Author: odersky

compiler/src/dotty/tools/dotc/cc/CheckCaptures.scala

@@ -1262,23 +1262,6 @@ class CheckCaptures extends Recheck, SymTransformer:
 
         if runInConstructor && savedEnv.owner.isClass then
           markFree(declaredCaptures, tree, addUseInfo = false)
-
-        if sym.owner.isStaticOwner
-            && !declaredCaptures.elems.isEmpty
-            && sym != defn.captureRoot
-            && !(sym.is(ModuleVal) && sym.owner.is(Package))
-                 // global modules that don't derive from capability can have captures
-                 // only if their fields have them, and then the field was already reported.
-            && !CaptureSet.isAssumedPure(sym.termRef)
-        then
-          def where =
-            if sym.effectiveOwner.is(Package) then "top-level definition"
-            else i"member of static ${sym.owner}"
-          report.warning(
-            em"""$sym has a non-empty capture set but will not be added as
-                |a capability to computed capture sets since it is globally accessible
-                |as a $where. Global values cannot be capabilities.""",
-            tree.namePos)
     end recheckValDef
 
     /** Recheck method definitions:

tests/neg-custom-args/captures/class-caps.check

@@ -22,12 +22,6 @@
 30 |    a + b
    |
    | longer explanation available when compiling with `-explain`
--- Warning: tests/neg-custom-args/captures/class-caps.scala:35:6 -------------------------------------------------------
-35 |  val console: Console^ = Console() // provide capability locally
-   |      ^^^^^^^
-   |      value console has a non-empty capture set but will not be added as
-   |      a capability to computed capture sets since it is globally accessible
-   |      as a member of static object Test2. Global values cannot be capabilities.
 -- [E007] Type Mismatch Error: tests/neg-custom-args/captures/class-caps.scala:37:46 -----------------------------------
 37 |  def addWritesToConsole: (Int, Int) -> Int = (a, b) => // error
    |                                              ^

tests/neg-custom-args/captures/indirect-avoid.check

@@ -7,18 +7,6 @@
    |    Note that capability nll is not included in capture set {ll}.
    |
    | longer explanation available when compiling with `-explain`
--- Warning: tests/neg-custom-args/captures/indirect-avoid.scala:24:6 ---------------------------------------------------
-24 |  val x1 = filterImpl1(LL())
-   |      ^^
-   |      value x1 has a non-empty capture set but will not be added as
-   |      a capability to computed capture sets since it is globally accessible
-   |      as a member of static object Test. Global values cannot be capabilities.
--- Warning: tests/neg-custom-args/captures/indirect-avoid.scala:25:6 ---------------------------------------------------
-25 |  val _: LL^{cap.rd}= x1
-   |      ^
-   |      value _$1 has a non-empty capture set but will not be added as
-   |      a capability to computed capture sets since it is globally accessible
-   |      as a member of static object Test. Global values cannot be capabilities.
 -- [E007] Type Mismatch Error: tests/neg-custom-args/captures/indirect-avoid.scala:26:14 -------------------------------
 26 |  val _: LL = x1 // error
    |              ^^

tests/neg-custom-args/captures/nonsensical-for-pure.check

@@ -2,9 +2,3 @@
 1 |val x: Int^ = 2  // error
   |       ^^^^
   |       Int is a pure type, it makes no sense to add a capture set to it
--- Warning: tests/neg-custom-args/captures/nonsensical-for-pure.scala:1:4 ----------------------------------------------
-1 |val x: Int^ = 2  // error
-  |    ^
-  |    value x has a non-empty capture set but will not be added as
-  |    a capability to computed capture sets since it is globally accessible
-  |    as a top-level definition. Global values cannot be capabilities.

tests/neg/mixed_cc.check

@@ -1,9 +1,3 @@
--- Warning: tests/neg/mixed_cc/B.scala:4:4 -----------------------------------------------------------------------------
-4 |val x: Object^{A.B} = ??? // error
-  |    ^
-  |    value x has a non-empty capture set but will not be added as
-  |    a capability to computed capture sets since it is globally accessible
-  |    as a top-level definition. Global values cannot be capabilities.
 -- Error: tests/neg/mixed_cc/B.scala:4:7 -------------------------------------------------------------------------------
 4 |val x: Object^{A.B} = ??? // error
   |       ^^^^^^^^^^^^