Annotate dump() methods with LLVM_DUMP_METHOD, addressing Richard Smith r259192 post commit comment.
clang part in r259232, this is the LLVM part of the patch.

llvm-svn: 259240
diff --git a/llvm/lib/Option/Option.cpp b/llvm/lib/Option/Option.cpp
index ebf05aa..d191e0e 100644
--- a/llvm/lib/Option/Option.cpp
+++ b/llvm/lib/Option/Option.cpp
@@ -82,7 +82,7 @@
   O << ">\n";
 }
 
-void Option::dump() const { print(dbgs()); }
+LLVM_DUMP_METHOD void Option::dump() const { print(dbgs()); }
 
 bool Option::matches(OptSpecifier Opt) const {
   // Aliases are never considered in matching, look through them.