Stop leaking MCRegisterInfo.



git-svn-id: https://llvm.org/svn/llvm-project/lldb/trunk@198177 91177308-0d34-0410-b5e6-96231b3b80d8
Fix a couple of memory leaks.



git-svn-id: https://llvm.org/svn/llvm-project/lldb/trunk@198178 91177308-0d34-0410-b5e6-96231b3b80d8