[ASan] Link with the dynamic runtime on OS X

[glider]

Summary

This patch changes the behavior of the -fsanitize=address flag, making it use the dynamic runtime library (libclang_rt.asan_osx_dynamic.dylib) instead of the static one. It also drops the CoreFoundation dependency, since the dynamic runtime doesn't need it.
This change is to be landed after http://llvm-reviews.chandlerc.com/D216

[Eugene.Zelenko]

Committed in rL173135.

lib/Driver/ToolChains.cpp

void DarwinClang::AddLinkRuntimeLibArgs(const ArgList &Args,
   if (Sanitize.needsAsanRt()) {
     if (Args.hasArg(options::OPT_dynamiclib) ||
         Args.hasArg(options::OPT_bundle)) {
       // Assume the binary will provide the ASan runtime.
     } else if (isTargetIPhoneOS()) {
       getDriver().Diag(diag::err_drv_clang_unsupported_per_platform)
         << "-fsanitize=address";
     } else {
-      AddLinkRuntimeLib(Args, CmdArgs, "libclang_rt.asan_osx.a", true);
+      AddLinkRuntimeLib(Args, CmdArgs, "libclang_rt.asan_osx_dynamic.dylib", true);
 
-      // The ASAN runtime library requires C++ and CoreFoundation.
+      // The ASAN runtime library requires C++.
       AddCXXStdlibLibArgs(Args, CmdArgs);
-      CmdArgs.push_back("-framework");
-      CmdArgs.push_back("CoreFoundation");
     }
   }
 
   // Otherwise link libSystem, then the dynamic runtime library, and finally any
   // target specific static runtime library.
   CmdArgs.push_back("-lSystem");
 
   // Select the dynamic runtime library and the target specific static library.