[gdb/tdep] Simplify amd64_windows_store_arg_in_reg

Simplify amd64_windows_store_arg_in_reg by:
- replacing memset with value initialization,
- making valbuf a gdb::array_view, allowing us to:
  - replace memcpy with std::copy, and
  - use valbuf.size () instead of arg->type->size (), and
- dropping the std::min in std::min (type->length (), (ULONGEST) 8), since
  we're already asserting that type->length () <= 8.

Suggested-By: Tom Tromey <tom@tromey.com>

Tested by rebuilding on x86_64-linux.
1 file changed