Use Process Plugin register indices when communicating with remote

Summary:
eRegisterKindProcessPlugin is used to store the register
indices used by the remote, and eRegisterKindLLDB is used
to store the internal lldb register indices. However, we're currently
using the lldb indices instead of the process plugin indices
when sending p/P packets. This will break if the remote uses
non-contiguous register indices.

Reviewers: jasonmolenda, clayborg

Subscribers: lldb-commits, sas

Differential Revision: http://reviews.llvm.org/D19305

llvm-svn: 267466
diff --git a/lldb/source/Plugins/Process/gdb-remote/GDBRemoteCommunicationClient.h b/lldb/source/Plugins/Process/gdb-remote/GDBRemoteCommunicationClient.h
index 311b0f3..33114d2 100644
--- a/lldb/source/Plugins/Process/gdb-remote/GDBRemoteCommunicationClient.h
+++ b/lldb/source/Plugins/Process/gdb-remote/GDBRemoteCommunicationClient.h
@@ -527,7 +527,7 @@
 
     bool
     ReadRegister(lldb::tid_t tid,
-                 uint32_t reg_num,
+                 uint32_t reg_num,   // Must be the eRegisterKindProcessPlugin register number, to be sent to the remote
                  StringExtractorGDBRemote &response);
 
     bool