Query the SYS_HEAPINFO semicall and do some basic verification of the
information via libc calls.

Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Reviewed-by: Thomas Huth <thuth@redhat.com>
Message-Id: <20210323165308.15244-10-alex.bennee@linaro.org>