compiler/ml_tag_switch.m:
As above. This fixes one of the two problems detected by Mantis bug #548.
tests/hard_coded/bug548.m:
A new small test case for Mantis bug #548. It includes, and documents,
both problems, and makes them visible in all hlc grades (not just pregen)
and at all optimization levels, provided inlining is turned on.
Since the second problem is not yet fixed, this test case
is not yet enabled.
tests/hard_coded/Mercury.options:
Enable inlining for the new test case.
compiler/loop_inv.m:
Rewrite the code that tickled Mantis bug #548. bug548.m takes over
from that code as an examplar of the bug, and the code, though short,
was conceptually more complex than its replacement.
Note similar issues with nearby code.
