[lldb] Test finding the first field of Observation.Extent

"Extent" is the class with the private discriminator, which we want to
test, but to test it we need to access its fields.

Author: augusto2112

lldb/test/API/lang/swift/observation/TestSwiftObservation.py

@@ -3,19 +3,26 @@
 from lldbsuite.test.decorators import *
 import lldbsuite.test.lldbutil as lldbutil
 
+
 class TestSwiftObservation(TestBase):
     NO_DEBUG_INFO_TESTCASE = True
+
     @swiftTest
     def test(self):
         """Test that types with private discriminators read from the file cache work"""
         self.build()
-        lldbutil.run_to_source_breakpoint(self, 'break here',
-                                          lldb.SBFileSpec('main.swift'))
+        lldbutil.run_to_source_breakpoint(
+            self, "break here", lldb.SBFileSpec("main.swift")
+        )
         # FIXME: Private discriminators are UUIDs in DWARF and pointers
         # in Reflection metafdata, making tham not comparable.
-        # rdar://74374120 
-        self.expect("settings set symbols.swift-validate-typesystem false")
-        self.expect("settings set target.experimental.swift-read-metadata-from-file-cache true")
+        # rdar://74374120
+        self.expect("settings set symbols.swift-enable-ast-context false")
+        self.expect(
+            "settings set target.experimental.swift-read-metadata-from-file-cache true"
+        )
         r = self.frame().FindVariable("r")
         extent = r.GetChildAtIndex(0)
         self.assertEqual(extent.GetName(), "extent")
+        context = extent.GetChildAtIndex(0)
+        self.assertEqual(context.GetName(), "context")