target/x86: Make get_phys_page_attrs_debug handle non-page-aligned addrs

Currently our implementations of SysemuCPUOps::get_phys_page_debug
and SysemuCPUOps::get_phys_page_attrs_debug are a mix of "accepts a
non-page-aligned virtual address and returns the corresponding
non-page-aligned physical address" and "only returns a page-aligned
physical address".  This is awkward for callsites, which in practice
all want the physical address for an arbitrary virtual address and
have to work around the possibility of getting a page-aligned
address, and it doesn't account for protection being possibly on a
sub-page-sized granularity.  We want to standardize on the
implementation having to handle non-page-aligned addresses.

For x86 this is simple: we just need to stop rounding down the
input address to a TARGET_PAGE boundary when calculating the
result to return.

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20260417173105.1648172-6-peter.maydell@linaro.org
Message-ID: <20260430093810.2762539-7-peter.maydell@linaro.org>
Signed-off-by: Philippe Mathieu-Daudé <philmd@linaro.org>