Report the detected host CPU in --version.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@88813 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Support/CommandLine.cpp b/lib/Support/CommandLine.cpp
index 07900d8..4275b28 100644
--- a/lib/Support/CommandLine.cpp
+++ b/lib/Support/CommandLine.cpp
@@ -1153,9 +1153,12 @@
 #ifndef NDEBUG
     OS << " with assertions";
 #endif
+    std::string CPU = sys::getHostCPUName();
+    if (CPU.empty()) CPU = "(unknown)";
     OS << ".\n"
        << "  Built " << __DATE__ << " (" << __TIME__ << ").\n"
        << "  Host: " << sys::getHostTriple() << '\n'
+       << "  Host CPU: " << CPU << '\n'
        << '\n'
        << "  Registered Targets:\n";