Add missing standard library includes

Add explicit includes for <cstdint>, <string>, and <limits> headers
that were previously implicitly included through other headers.

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude <noreply@anthropic.com>

Author: nindanaoto

llvm/include/llvm/Demangle/MicrosoftDemangleNodes.h

@@ -16,6 +16,8 @@
 #include "llvm/Demangle/DemangleConfig.h"
 #include "llvm/Demangle/StringView.h"
 #include <array>
+#include <cstdint>
+#include <string>
 
 namespace llvm {
 namespace itanium_demangle {

llvm/utils/benchmark/src/benchmark_register.h

@@ -1,6 +1,7 @@
 #ifndef BENCHMARK_REGISTER_H
 #define BENCHMARK_REGISTER_H
 
+#include <limits>
 #include <vector>
 
 #include "check.h"