Add a missing declaration of Log in lldb.

Bill accepted this commit for the 3.4 release.

The build was failing with:
/tmp/buildd/llvm-toolchain-3.4-3.4~+/tools/lldb/source/Host/common/Host.cpp:1222:30: error: request for member 'Printf' in 'log', which is of non-class type 'double(double)throw ()'
log->Printf("Host::GetLLDBPath(ePathTypeLLDBTempSystemDir) => '%s'", g_lldb_tmp_dir.GetCString());



git-svn-id: https://llvm.org/svn/llvm-project/lldb/branches/release_34@197376 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/source/Host/common/Host.cpp b/source/Host/common/Host.cpp
index ffcf657..47f3c10 100644
--- a/source/Host/common/Host.cpp
+++ b/source/Host/common/Host.cpp
@@ -1217,6 +1217,7 @@
                 }
                 if (tmpdir_cstr)
                 {
+                    Log *log(lldb_private::GetLogIfAllCategoriesSet (LIBLLDB_LOG_THREAD));
                     g_lldb_tmp_dir.SetCString(tmpdir_cstr);
                     if (log)
                         log->Printf("Host::GetLLDBPath(ePathTypeLLDBTempSystemDir) => '%s'", g_lldb_tmp_dir.GetCString());