Fix context comparisons

pkg/analyzer/lib/src/dart/sdk/sdk.dart

Index: pkg/analyzer/lib/src/dart/sdk/sdk.dart
diff --git a/pkg/analyzer/lib/src/dart/sdk/sdk.dart b/pkg/analyzer/lib/src/dart/sdk/sdk.dart
index 2e71aebc2c7c352c1011972a25938026af09da84..dbf811c7c01b1df326812e8ab4b61baa542adab7 100644
--- a/pkg/analyzer/lib/src/dart/sdk/sdk.dart
+++ b/pkg/analyzer/lib/src/dart/sdk/sdk.dart
@@ -680,8 +680,8 @@ class FolderBasedDartSdk extends AbstractDartSdk {
       return null;
     }
     pathos.Context pathContext = resourceProvider.pathContext;
-    if (pathContext != pathos.context) {
-      // The only time this will be true is if pathContext == posix and
+    if (pathContext.style != pathos.context.style) {
+      // This will only be true if pathContext == posix and
       // pathos.context == windows, which only happens when running tests.
       if (exec.startsWith(new RegExp('[a-zA-Z]:'))) {
         exec = exec.substring(2);