fix: do not remove libc memmove until performance comparisons have been conducted

src/fastmem.zig

@@ -2,10 +2,14 @@ const std = @import("std");
 const builtin = @import("builtin");
 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.
+/// Same as @memmove 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 {
-    @memmove(dest, source);
+    if (builtin.link_libc) {
+        _ = memmove(dest.ptr, source.ptr, source.len * @sizeOf(T));
+    } else {
+        @memmove(dest, source);
+    }
 }
 
 /// Same as @memcpy but prefers libc memcpy if it is available