iASL: Ensure valid C identifiers in output files.

For the options that create tables in C, ensure that the C names that
are emitted consist of valid C characters. The OemTableID is used
to generate unique C identifiers. Convert any non-alphanumeric
characters to underscores.
iASL: -so option, add ACPI object types to offset table.

Add the standard ACPI objects type for each object in the emitted
offset table. Requested by BIOS developers.