cmd/compile/internal/typebits: relax alignment check

cmd/compile/internal/typebits: relax alignment check

Now we have 8-byte alignment types on 32-bit system, so in some rare
case, e.g, generated wrapper for embedded interface, the function
argument may need more than 4 byte alignment. We could pad somehow, but
this is a rare case which makes it hard to ensure that we've got it right.

So relaxing the check for argument and return value region of the stack.

Fixes #54991

Change-Id: I34986e17a920254392a39439ad3dcb323da2ea8d
Reviewed-on: https://go-review.googlesource.com/c/go/+/431098
Reviewed-by: Keith Randall <khr@golang.org>
TryBot-Result: Gopher Robot <gobot@golang.org>
Reviewed-by: Cherry Mui <cherryyz@google.com>
Run-TryBot: Cuong Manh Le <cuong.manhle.vn@gmail.com>
Auto-Submit: Keith Randall <khr@golang.org>
Reviewed-by: Keith Randall <khr@google.com>