[flang] fix compiler report error on windows

[lipracer]

No description provided.

[llvmbot]

@llvm/pr-subscribers-flang-runtime

Author: long.chen (lipracer)

Changes

---

Full diff: https://github.com/llvm/llvm-project/pull/76491.diff

1 Files Affected:

• (modified) flang/runtime/tools.h (+1-1)

diff --git a/flang/runtime/tools.h b/flang/runtime/tools.h
index ff05e76c8bb7b2..84a2a82e3b2ab8 100644
--- a/flang/runtime/tools.h
+++ b/flang/runtime/tools.h
@@ -108,7 +108,7 @@ static inline RT_API_ATTRS std::optional<std::int64_t> GetInt64Safe(
   case 16: {
     using Int128 = CppTypeFor<TypeCategory::Integer, 16>;
     auto n{*reinterpret_cast<const Int128 *>(p)};
-    std::int64_t result = n;
+    std::int64_t result = static_cast<std::int64_t>(n);
     if (result == n) {
       return result;
     }