Make sure switch covers all values.

llvm-svn: 193052
diff --git a/lldb/source/Plugins/Process/POSIX/ProcessMessage.cpp b/lldb/source/Plugins/Process/POSIX/ProcessMessage.cpp
index bdb7804..5c53627 100644
--- a/lldb/source/Plugins/Process/POSIX/ProcessMessage.cpp
+++ b/lldb/source/Plugins/Process/POSIX/ProcessMessage.cpp
@@ -248,6 +248,9 @@
     case eNewThreadMessage:
         str = "eNewThreadMessage";
         break;
+    case eExecMessage:
+        str = "eExecMessage";
+        break;
     }
 #endif