Include BuiltinAttributes.h in llvm-prettyprinters/gdb/mlir-support.cpp

This header was introduced in c7cae0e4fa4e1ed4bdca186096a408578225fc2b.

GitOrigin-RevId: 1b404ad51e93724ecd74c66f1a11f03568398c57
diff --git a/llvm-prettyprinters/gdb/mlir-support.cpp b/llvm-prettyprinters/gdb/mlir-support.cpp
index 4f94b3c..a65f624 100644
--- a/llvm-prettyprinters/gdb/mlir-support.cpp
+++ b/llvm-prettyprinters/gdb/mlir-support.cpp
@@ -1,3 +1,4 @@
+#include "mlir/IR/BuiltinAttributes.h"
 #include "mlir/IR/BuiltinTypes.h"
 #include "mlir/IR/Identifier.h"
 #include "mlir/IR/Location.h"