Use a more appropriate invalidation kind in the devirtualizer.

We're not touching branches, so we do not need to invalidate those.

lib/SILOptimizer/Transforms/Devirtualizer.cpp

@@ -41,7 +41,7 @@ class Devirtualizer : public SILFunctionTransform {
                        << " *****\n");
 
     if (devirtualizeAppliesInFunction(F, CHA))
-      invalidateAnalysis(SILAnalysis::InvalidationKind::FunctionBody);
+      invalidateAnalysis(SILAnalysis::InvalidationKind::CallsAndInstructions);
   }
 
   StringRef getName() override { return "Devirtualizer"; }