Address PR feedback: Remove unnecessary tests and fix fourslash normalization

- Remove internal/fourslash/tests/gen/locationlink_endtoend_test.go (coverage exists elsewhere)
- Remove testdata/tests/cases/compiler/gotoDefinitionLocationLink.ts (not a language service test)
- Fix fourslash.go to properly handle DefinitionLinks by setting additionalSpan instead of normalizing to Locations
- When single DefinitionLink with origin selection range, use it as additionalSpan for baseline comparison

Co-authored-by: DanielRosenwasser <972891+DanielRosenwasser@users.noreply.github.com>

Author: Copilot

internal/fourslash/fourslash.go

@@ -886,24 +886,33 @@ func (f *FourslashTest) VerifyBaselineGoToDefinition(
 		}
 
 		var resultAsLocations []lsproto.Location
+		var additionalSpan *lsproto.Location
 		if result.Locations != nil {
 			resultAsLocations = *result.Locations
 		} else if result.Location != nil {
 			resultAsLocations = []lsproto.Location{*result.Location}
 		} else if result.DefinitionLinks != nil {
-			// Convert DefinitionLinks to Locations for baseline comparison
+			// For DefinitionLinks, extract the target locations and optionally set additionalSpan
 			resultAsLocations = make([]lsproto.Location, len(*result.DefinitionLinks))
 			for i, link := range *result.DefinitionLinks {
 				resultAsLocations[i] = lsproto.Location{
 					Uri:   link.TargetUri,
 					Range: link.TargetSelectionRange,
 				}
 			}
+			// If there's a single result and it has an origin selection range, use it as additionalSpan
+			if len(*result.DefinitionLinks) == 1 && (*result.DefinitionLinks)[0].OriginSelectionRange != nil {
+				additionalSpan = &lsproto.Location{
+					Uri:   ls.FileNameToDocumentURI(markerOrRange.GetMarker().FileName()),
+					Range: *(*result.DefinitionLinks)[0].OriginSelectionRange,
+				}
+			}
 		}
 
 		f.baseline.addResult("goToDefinition", f.getBaselineForLocationsWithFileContents(resultAsLocations, baselineFourslashLocationsOptions{
-			marker:     markerOrRange.GetMarker(),
-			markerName: "/*GO TO DEFINITION*/",
+			marker:         markerOrRange.GetMarker(),
+			markerName:     "/*GO TO DEFINITION*/",
+			additionalSpan: additionalSpan,
 		}))
 	}