PR go/90482
    compiler: make value method of direct interface type takes pointer
    
    Currently, a value method of a direct interface type takes the
    value of the receiver, which is pointer shaped, as the first
    parameter. When this method is called through interface, we
    actually pass the interface data as a pointer. On most platforms
    this is ok, as the underlying calling convention is the same,
    except that on SPARC32, the calling convention is actually
    different.
    
    This CL changes the method function actually takes a pointer.
    The function will convert the pointer to the pointer-shaped
    receiver type (a no-op conversion from machine code's aspect).
    For a direct call, in the caller we convert the receiver to a
    pointer (also no-op conversion) before invoking the method. For
    an interface call, we pass the pointer as before. This way, it is
    consistent that we always pass a pointer.
    
    Hopefully this fixes SPARC32 build and https://gcc.gnu.org/PR90482.
    
    Reviewed-on: https://go-review.googlesource.com/c/gofrontend/+/177758

From-SVN: r271310