This patch fixes so that declspec attributes are forwarded
to the alias declaration.
Before this patch this would assert:
class Test { int a; };
using AlignedTest = __declspec(align(16)) const Test;
static_assert(alignof(AlignedTest) == 16, "error");
But afterwards it behaves the same as MSVC does and doesn't
assert.
Fixes: llvm/llvm-project#60513
Reviewed By: aaron.ballman
Differential Revision: https://reviews.llvm.org/D143632
