compat : rebase and build for windows xp.

Author: guilt

ggml.c

@@ -190,8 +190,15 @@ void ggml_print_backtrace(void) {
 #endif
 
 #if defined(_MSC_VER) || defined(__MINGW32__)
+
 #define GGML_ALIGNED_MALLOC(size) _aligned_malloc(size, GGML_MEM_ALIGN)
 #define GGML_ALIGNED_FREE(ptr)    _aligned_free(ptr)
+
+#if defined(__MINGW32__) && !defined(_aligned_malloc)
+  _CRTIMP void __cdecl _aligned_free(void *_Memory);
+  _CRTIMP void *__cdecl _aligned_malloc(size_t _Size,size_t _Alignment);
+#endif
+
 #else
 inline static void * ggml_aligned_malloc(size_t size) {
     if (size == 0) {

llama.cpp

@@ -904,6 +904,7 @@ struct llama_mmap {
         }
 
         if (prefetch) {
+#if WINVER >= 0x0602 // Windows 8 or higher define this function.
             // PrefetchVirtualMemory is only present on Windows 8 and above, so we dynamically load it
             BOOL (WINAPI *pPrefetchVirtualMemory) (HANDLE, ULONG_PTR, PWIN32_MEMORY_RANGE_ENTRY, ULONG);
             HMODULE hKernel32 = GetModuleHandleW(L"kernel32.dll");
@@ -921,6 +922,9 @@ struct llama_mmap {
                             llama_format_win_err(GetLastError()).c_str());
                 }
             }
+#else
+                throw std::runtime_error("PrefetchVirtualMemory unavailable");
+#endif
         }
     }