[Driver] Quote clang full version in dwarf producer when invoking cc1as

Convenience to allow easy copy-n-paste from clang -v output when
reproducing cc1as comandline.

rdar://problem/23959295

llvm-svn: 264813
diff --git a/clang/lib/Driver/Tools.cpp b/clang/lib/Driver/Tools.cpp
index a64961c..b441c72 100644
--- a/clang/lib/Driver/Tools.cpp
+++ b/clang/lib/Driver/Tools.cpp
@@ -6226,7 +6226,8 @@
     // Set the AT_producer to the clang version when using the integrated
     // assembler on assembly source files.
     CmdArgs.push_back("-dwarf-debug-producer");
-    CmdArgs.push_back(Args.MakeArgString(getClangFullVersion()));
+    std::string QuotedClangVersion("'" + getClangFullVersion() + "'");
+    CmdArgs.push_back(Args.MakeArgString(QuotedClangVersion));
 
     // And pass along -I options
     Args.AddAllArgs(CmdArgs, options::OPT_I);