Fix warnings generated by clang-cl.

There were a couple of real bugs here regarding error checking and
signed/unsigned comparisons, but mostly these were just noise.

There was one class of bugs fixed here which is particularly
annoying, dealing with MSVC's non-standard behavior regarding
the underlying type of enums.  See the comment in
lldb-enumerations.h for details.  In short, from now on please use
FLAGS_ENUM and FLAGS_ANONYMOUS_ENUM when defining enums which
contain values larger than can fit into a signed integer.

llvm-svn: 233943
diff --git a/lldb/source/Host/windows/ConnectionGenericFileWindows.cpp b/lldb/source/Host/windows/ConnectionGenericFileWindows.cpp
index bbf3150..e2b23d0 100644
--- a/lldb/source/Host/windows/ConnectionGenericFileWindows.cpp
+++ b/lldb/source/Host/windows/ConnectionGenericFileWindows.cpp
@@ -208,9 +208,9 @@
             TimeValue time_value;
             time_value.OffsetWithMicroSeconds(timeout_usec);
             DWORD milliseconds = time_value.milliseconds();
-            result = ::WaitForMultipleObjects(llvm::array_lengthof(m_event_handles), m_event_handles, FALSE, milliseconds);
+            DWORD wait_result = ::WaitForMultipleObjects(llvm::array_lengthof(m_event_handles), m_event_handles, FALSE, milliseconds);
             // All of the events are manual reset events, so make sure we reset them to non-signalled.
-            switch (result)
+            switch (wait_result)
             {
                 case WAIT_OBJECT_0 + kBytesAvailableEvent:
                     break;