[util] Implement replaceNaN for non-x86 platforms

src/util/util_vector.h

@@ -151,12 +151,18 @@ namespace dxvk {
   static_assert(sizeof(Vector4i) == sizeof(int)   * 4);
 
   inline Vector4 replaceNaN(Vector4 a) {
+    #ifdef DXVK_ARCH_X86
     Vector4 result;
     __m128 value = _mm_load_ps(a.data);
     __m128 mask  = _mm_cmpeq_ps(value, value);
            value = _mm_and_ps(value, mask);
     _mm_store_ps(result.data, value);
     return result;
+    #else
+    for (int i = 0; i < 4; i++)
+      a[i] = std::isnan(a[i]) ? 0.0f : a[i];
+    return a;
+    #endif
   }
 
 }