fix dartanalyzer find options in bazel workspace

pkg/analyzer/lib/src/context/builder.dart

Index: pkg/analyzer/lib/src/context/builder.dart
diff --git a/pkg/analyzer/lib/src/context/builder.dart b/pkg/analyzer/lib/src/context/builder.dart
index 05421729840a748034c0dfa91208f933c66ed52c..ea35756ee2f1f635e97ae7156921bda2acd83d18 100644
--- a/pkg/analyzer/lib/src/context/builder.dart
+++ b/pkg/analyzer/lib/src/context/builder.dart
@@ -722,8 +722,7 @@ class _BasicWorkspace extends Workspace {
   final ResourceProvider provider;
 
   /**
-   * The absolute workspace root path (the directory containing the `.jiri_root`
-   * directory).
+   * The absolute workspace root path.
    */
   final String root;
 
@@ -769,7 +768,15 @@ class _BasicWorkspace extends Workspace {
    * Find the basic workspace that contains the given [path].
    */
   static _BasicWorkspace find(
-      ResourceProvider resourceProvider, String path, ContextBuilder builder) {
-    return new _BasicWorkspace._(resourceProvider, path, builder);
+      ResourceProvider provider, String path, ContextBuilder builder) {
+    Context context = provider.pathContext;
+
+    // Ensure that the path is absolute and normalized.
+    if (!context.isAbsolute(path)) {
+      throw new ArgumentError('not absolute: $path');
+    }
+    path = context.normalize(path);
+
+    return new _BasicWorkspace._(provider, path, builder);
   }
 }