Silence a bunch of implicit fallthrough warnings

llvm-svn: 321115
diff --git a/clang/lib/AST/ASTDumper.cpp b/clang/lib/AST/ASTDumper.cpp
index 157b29f..73154ba 100644
--- a/clang/lib/AST/ASTDumper.cpp
+++ b/clang/lib/AST/ASTDumper.cpp
@@ -1537,7 +1537,7 @@
     case TSK_ExplicitInstantiationDefinition:
       if (!DumpExplicitInst)
         break;
-      // Fall through.
+      LLVM_FALLTHROUGH;
     case TSK_Undeclared:
     case TSK_ImplicitInstantiation:
       if (DumpRefOnly)