ACPICA: iASL: Enhance detection of non-ascii or corrupted input files.

ACPICA commit 08170904011f1e8f817d9e3a9f2bb2438aeacf60

For the compiler part (not disassembler).
- Characters not within a comment must be be ASCII (0-0x7F), and
now either printable or a "space" character.
Provides better detection of files that cannot be compiled.

This patch only affects iASL which is not in the Linux upstream.

Link: https://github.com/acpica/acpica/commit/08170904
Signed-off-by: Bob Moore <robert.moore@intel.com>
Signed-off-by: Lv Zheng <lv.zheng@intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>