cr: Print a list of closest matching targets when no match is found

tools/cr/cr/targets/target.py

Index: tools/cr/cr/targets/target.py
diff --git a/tools/cr/cr/targets/target.py b/tools/cr/cr/targets/target.py
index e02bdb04ec2ff959a15840422d9ac70da6a201ac..0780ae936c304f202b3e978882570cc5cc306aa2 100644
--- a/tools/cr/cr/targets/target.py
+++ b/tools/cr/cr/targets/target.py
@@ -117,6 +117,11 @@ class Target(cr.Config, cr.AutoExport):
         if not target.valid:
           print 'Invalid target {0} as {1}'.format(
               target_name, target.build_target)
+          guesses = cr.Builder.GuessTargets(context, target_name)
+          if guesses:
+            print 'Did you mean {0}?'.format(
+                ', '.join(guesses[:-1]) + ' or ' + guesses[-1]
+                if len(guesses) > 1 else guesses[0])
           exit(1)
         return target
     print 'Unknown target {0}'.format(target_name)