message: Fix an ASAN detected bug introduced by cr/227067644.  While MLFunctions always
  have one block, CFG Functions don't necessarily have one (e.g. when they are
  being first constructed by the parser).
diff: @@ -163,10 +163,13 @@ protected:
  /// automatically inserted at an insertion point. The builder is copyable.
  class FuncBuilder : public Builder {
  public:
  - /// Create an ML function builder and set the insertion point to the start of
  + /// Create a function builder and set the insertion point to the start of
  /// the function.
  FuncBuilder(Function *func) : Builder(func->getContext()), function(func) {
  + if (!func->empty())
  setInsertionPoint(&func->front(), func->front().begin());
  + else
  + clearInsertionPoint();
  }
  /// Create a function builder and set insertion point to the given statement,
  