Don't look for the forked SDK in the migration script.

Now that we're unforked, this is no longer needed.

Change-Id: I7016d34e11138ff21bcdb4af2795f7d4faa3e0fb
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/147817
Auto-Submit: Bob Nystrom <[email protected]>
Commit-Queue: Nicholas Shahan <[email protected]>
Reviewed-by: Nicholas Shahan <[email protected]>

Author: munificent

tools/migration/lib/src/analyze.dart

@@ -96,10 +96,7 @@ Future<Map<String, List<_StaticError>>> _runAnalyzer(String inputDir,
       "${nnbd ? ' with NNBD' : ''}...");
   var result = await Process.run("dartanalyzer", [
     "--packages=${p.join(sdkRoot, '.packages')}",
-    if (nnbd) ...[
-      "--dart-sdk=$nnbdSdkBuildDir",
-      "--enable-experiment=non-nullable",
-    ],
+    if (nnbd) "--enable-experiment=non-nullable",
     "--format=machine",
     inputDir,
   ]);

tools/migration/lib/src/io.dart

@@ -6,8 +6,6 @@ import 'dart:io';
 
 import 'package:path/path.dart' as p;
 
-import 'log.dart';
-
 /// True if the file system should be left untouched.
 bool dryRun = false;
 
@@ -16,21 +14,6 @@ final String sdkRoot =
 
 final String testRoot = p.join(sdkRoot, "tests");
 
-final String nnbdSdkBuildDir = () {
-  var buildDir = Platform.isMacOS ? "xcodebuild" : "out";
-  var path = p.join(sdkRoot, buildDir, "ReleaseX64NNBD", "dart-sdk");
-
-  if (!Directory(path).existsSync()) {
-    print(red("Could not find an NNBD SDK at $path"));
-    print(red("Please build the NNBD SDK using:"));
-    print("");
-    print(red("  ./tools/build.py -m release --nnbd create_sdk"));
-    exit(1);
-  }
-
-  return path;
-}();
-
 /// Copies the file from [from] to [to], which are both assumed to be relative
 /// paths inside "tests".
 void copyFile(String from, String to) {