Hide some more LLVM-internal command line args.
Add fixes for Win64
Merge pull request #655 from klickverbot/hide-llvm-args

Hide some more LLVM-internal command line args.
Remove -noruntime as adverticed
Add -L=-lcurl to std.net.curl unit test.

There is no pragma to pull in this library. Therefore specify the lib on the command line.
Also remove emptymain.d as we now have the -main switch.
Fold in dmd-testsuite merge conflict fix.
Remove unused 'seenTemplateInstances' mechanism.
Use --gc-sections on Linux.

This was painful.