if and do dead code removal

Signed-off-by: Rick Taylor <rick@tropicalstormsoftware.com>
More dead-code elimination

Signed-off-by: Rick Taylor <rick@tropicalstormsoftware.com>
More deadcode

Signed-off-by: Rick Taylor <rick@tropicalstormsoftware.com>
Fix a slightly too agressive dead-code elimination
Now handles complex lvalues

Signed-off-by: Rick Taylor <rick@tropicalstormsoftware.com>
Catch a bug with if handling

Signed-off-by: Rick Taylor <rick@tropicalstormsoftware.com>
Fixed loop checking
Improved constant (no side-effects) handling

Signed-off-by: Rick Taylor <rick@tropicalstormsoftware.com>