Split posCC from pos tests

I believe the timeout was simply that we have to many pos tests, so theior compilation takes more than the
limit of 20 minutes. Testing this hypothesis by moving pos-custumargs/captures tests into a separate
top-level test posCC

Author: odersky

compiler/test/dotty/tools/dotc/CompilationTests.scala

@@ -37,7 +37,6 @@ class CompilationTests {
       compileFilesInDir("tests/pos-special/sourcepath/outer", defaultOptions.and("-sourcepath", "tests/pos-special/sourcepath")),
       compileFile("tests/pos-special/sourcepath/outer/nested/Test4.scala", defaultOptions.and("-sourcepath", "tests/pos-special/sourcepath")),
       compileFilesInDir("tests/pos-scala2", defaultOptions.and("-source", "3.0-migration")),
-      compileFilesInDir("tests/pos-custom-args/captures", defaultOptions.and("-language:experimental.captureChecking")),
       compileFile("tests/pos-special/utf8encoded.scala", defaultOptions.and("-encoding", "UTF8")),
       compileFile("tests/pos-special/utf16encoded.scala", defaultOptions.and("-encoding", "UTF16")),
       compileDir("tests/pos-special/i18589", defaultOptions.and("-Wsafe-init").without("-Ycheck:all")),
@@ -56,6 +55,12 @@ class CompilationTests {
     aggregateTests(tests*).checkCompile()
   }
 
+  @Test def posCC: Unit =
+    given TestGroup = TestGroup("compilePosCC")
+    aggregateTests(
+      compileFilesInDir("tests/pos-custom-args/captures", defaultOptions.and("-language:experimental.captureChecking")),
+    ).checkCompile()
+
   @Test def rewrites: Unit = {
     implicit val testGroup: TestGroup = TestGroup("rewrites")