Fix the documentation of getDefaultSubtargetFeatures.

Patch by David Nadlinger.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@192098 91177308-0d34-0410-b5e6-96231b3b80d8
Remove getEHExceptionRegister and getEHHandlerRegister.

They haven't been used for a long time. Patch by MathOnNapkins.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@192099 91177308-0d34-0410-b5e6-96231b3b80d8
Remove dead code.

Support for exception handling in the legacy JIT was removed in r181354 and
this code was dead since then.

Thanks to Yaron Keren for noticing it.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@192101 91177308-0d34-0410-b5e6-96231b3b80d8