Recognize sparc64 as an alias for sparcv9 triples.

Patch by Brad Smith!

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@181808 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Support/Triple.cpp b/lib/Support/Triple.cpp
index 412e34c..7c02ffb 100644
--- a/lib/Support/Triple.cpp
+++ b/lib/Support/Triple.cpp
@@ -239,7 +239,7 @@
     .Case("hexagon", Triple::hexagon)
     .Case("s390x", Triple::systemz)
     .Case("sparc", Triple::sparc)
-    .Case("sparcv9", Triple::sparcv9)
+    .Cases("sparcv9", "sparc64", Triple::sparcv9)
     .Case("tce", Triple::tce)
     .Case("xcore", Triple::xcore)
     .Case("nvptx", Triple::nvptx)