libxl: Ensure all _hidden functions use libxl__ prefix (manual part)

libxl: Ensure all _hidden functions use libxl__ prefix (manual part)

This patch covers the remaining functions identified by:
  rgrep _hidden tools/libxl/*.h | grep -v libxl__

sed -i -e 's/XL_LOG/LIBXL__LOG/g' tools/libxl/*.[ch]
sed -i -e 's/xl_log/libxl__log/g' tools/libxl/*.[ch]
sed -i -e 's/\(build_\(pre\|post\|pv\|hvm\)\)/libxl__\1/g' tools/libxl/*.[ch]
sed -i -e 's/is_hvm/libxl__domain_is_hvm/g' tools/libxl/*.[ch]
sed -i -e 's/get_shutdown_reason/libxl__domain_shutdown_reason/g' tools/libxl/*.[ch]
sed -i -e 's/restore_common/libxl__domain_restore_common/g' tools/libxl/*.[ch]
sed -i -e 's/core_suspend/libxl__domain_suspend_common/g' tools/libxl/*.[ch]
sed -i -e 's/save_device_model/libxl__domain_save_device_model/g' tools/libxl/*.[ch]
sed -i -e 's/device_disk_backend_type_of_phystype/libxl__device_disk_backend_type_of_phystype/g' tools/libxl/*.[ch]
sed -i -e 's/\<libxl_blktap_enabled\>/libxl__blktap_enabled/g'  tools/libxl/*.[ch]
sed -i -e 's/\<libxl_blktap_devpath\>/libxl__blktap_devpath/g'  tools/libxl/*.[ch]

Add _hidden to libxl__blktap_enabled and libxl__blktap_devpath

Inline dominfo_libxl__domain_shutdown_reason(info) into
libxl__domain_shutdown_reason, its only caller.

Signed-off-by: Ian Campbell <ian.campbell@citrix.com>
Signed-off-by: Ian Jackson <ian.jackson@eu.citrix.com>