fix call to std::min() with potentially multiple arg types

Summary: `std::min` requires both its arguments to have identical types. In this call-site in `folly/algorithm/simd/test/ContainsTest.cpp`, one argument has type `unsigned long` and the other has type `std::size_t` (from `std::vector<T>::size_type`). These two types may be the same on some platforms, in that `size_t` is an alias to `unsigned long` on some platforms, but this is not specified. And this assumption does in practice fail, breaking the build.

Differential Revision: D64643993

fbshipit-source-id: 4559f14c2bb548036c7bab408c61b46380603e8a

folly/algorithm/simd/test/ContainsTest.cpp

@@ -138,8 +138,8 @@ TYPED_TEST(ContainsTest, Basic) {
 
   for (std::size_t size = 0; size != 100; ++size) {
     std::vector<T> buf(size, T{0});
-    for (std::size_t offset = 0; offset != std::min(32UL, buf.size());
-         ++offset) {
+    auto const bound = std::min(std::size_t(32), size);
+    for (std::size_t offset = 0; offset != bound; ++offset) {
       folly::span<T> haystack(buf.data() + offset, buf.data() + buf.size());
       T needle{1};
       testSimdContainsVerify(haystack, needle, /*expected*/ false);