fix:use builtin memmove

src/fastmem.zig

@@ -5,18 +5,7 @@ const assert = std.debug.assert;
 /// Same as std.mem.copyForwards/Backwards but prefers libc memmove if it is
 /// available because it is generally much faster.
 pub inline fn move(comptime T: type, dest: []T, source: []const T) void {
-    if (builtin.link_libc) {
-        _ = memmove(dest.ptr, source.ptr, source.len * @sizeOf(T));
-    } else {
-        // Depending on the ordering of the copy, we need to use the
-        // proper call here. Unfortunately this function call is
-        // too generic to know this at comptime.
-        if (@intFromPtr(dest.ptr) <= @intFromPtr(source.ptr)) {
-            std.mem.copyForwards(T, dest, source);
-        } else {
-            std.mem.copyBackwards(T, dest, source);
-        }
-    }
+    @memmove(dest, source);
 }
 
 /// Same as @memcpy but prefers libc memcpy if it is available