Reland "Add support to -Wa,--version in clang""

This relands commit 3cc3c0f with fixed
test cases, which was reverted by commit
bf2479c.

Author: jcai19

clang/lib/Driver/ToolChains/Clang.cpp

@@ -2552,6 +2552,8 @@ static void CollectArgsForIntegratedAssembler(Compilation &C,
         // -fdebug-compilation-dir (without '=') here.
         CmdArgs.push_back("-fdebug-compilation-dir");
         CmdArgs.push_back(Value.data());
+      } else if (Value == "--version") {
+        D.PrintVersion(C, llvm::outs());
       } else {
         D.Diag(diag::err_drv_unsupported_option_argument)
             << A->getOption().getName() << Value;

clang/test/Driver/as-version.s

@@ -0,0 +1,5 @@
+// Test version information.
+
+// RUN: %clang -Wa,--version -c -fintegrated-as %s -o /dev/null \
+// RUN:   | FileCheck --check-prefix=IAS %s
+// IAS: clang version