For mips3 and alpha, put the assembler file directives in separate

variables and disable the Alpha assembler for now, since it has been
shown to fail.

The Alpha failure can be shown by adding the following numbers:

FFFFFFFFFFFFFF0000FF2E00000000EBFFFFFF0000D1
FFFFFFFFFFFFFFFFFFFFFFFFFFFFFF46FFE0FFFF0000

The result is:

1FFFFFFFFFFFEFF0000FF2E0000000032FFE0FEFF00D1

The result should really be:

1FFFFFFFFFFFFFF0000FF2E0000000032FFE0FEFF00D1