Attempt to fix the windows bot

Change-Id: I0fbe011399826002e805fda58d3d8a8f3d6693dd
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/416021
Reviewed-by: Samuel Rawlins <[email protected]>
Auto-Submit: Brian Wilkerson <[email protected]>

Author: bwilkerson

pkg/analysis_server/test/abstract_single_unit.dart

@@ -50,7 +50,7 @@ class AbstractSingleUnitTest extends AbstractContextTest {
     var unitResult = libraryResult?.unitWithPath(file.path);
     unitResult ??= await super.getResolvedUnit(file);
 
-    if (file.path == testFilePath) {
+    if (file.path == convertPath(testFilePath)) {
       testLibraryResult = libraryResult;
       testAnalysisResult = unitResult;
       testUnit = unitResult.unit;