Fix 64-bit integers on `x86_64-linux-gnu`

The __LP64__ macros work fine on aarch64, but they don't seem to do much on x86_64

SDL3-CS/generate_bindings.py

@@ -262,9 +262,11 @@ base_command = [
     "bool=SDLBool",  # treat bool as C# helper type
     "__va_list=byte*",
     "__va_list_tag=byte",
+    "Sint64=long",
+    "Uint64=ulong",
 
     "--with-type",
-    "*=int", # all types should be ints by default
+    "*=int",  # all enum types should be ints by default
 
     "--nativeTypeNamesToStrip",
     "unsigned int",