Clang: Decrease order of snippets

The order is 0 by default and thus the snippet items were at the very
top, e.g.:

  enum EnumType { EnumValue };

  void f()
  {
      EnumType et = // Complete here and see snippet items at top
  }

Change-Id: I70a160d102b91a2589972354c50aa5f0b29323e8
Reviewed-by: Tim Jenssen <tim.jenssen@qt.io>

src/plugins/clangcodemodel/clangcompletionassistprocessor.cpp

@@ -136,7 +136,8 @@ using namespace CPlusPlus;
 using namespace TextEditor;
 
 ClangCompletionAssistProcessor::ClangCompletionAssistProcessor()
-    : m_completionOperator(T_EOF_SYMBOL)
+    : CppCompletionAssistProcessor(100)
+    , m_completionOperator(T_EOF_SYMBOL)
 {
 }