Add back <stdint.h> include to NVVMIntrinsicUtils

Add the <stdint.h> header include back into NVVMIntrinsicUtils.h after
rebasing the commit which renamed it to a point after the original
NVVMIntrinsicFlags.h version was edited to include <stdint>

This extra include was originally added by:
  f33e236 [clang][Modules] Fixing Build Breaks When -DLLVM_ENABLE_MODULES=ON (#119473)

Author: LewisCrawford

llvm/include/llvm/IR/NVVMIntrinsicUtils.h

@@ -15,6 +15,8 @@
 #ifndef LLVM_IR_NVVMINTRINSICUTILS_H
 #define LLVM_IR_NVVMINTRINSICUTILS_H
 
+#include <stdint.h>
+
 #include "llvm/ADT/APFloat.h"
 #include "llvm/IR/Intrinsics.h"
 #include "llvm/IR/IntrinsicsNVPTX.h"