Improve JIT error message for users crazy enough to use -march with JIT, and
mention -version in messages about missing targets.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@81272 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Support/TargetRegistry.cpp b/lib/Support/TargetRegistry.cpp
index 79f30a7..5896447 100644
--- a/lib/Support/TargetRegistry.cpp
+++ b/lib/Support/TargetRegistry.cpp
@@ -40,7 +40,8 @@
   }
 
   if (!Best) {
-    Error = "No available targets are compatible with this triple";
+    Error = "No available targets are compatible with this triple, "
+      "see -version for the available targets.";
     return 0;
   }