Eliminate temporary locals for some expressions

runtime/vm/bit_vector.h

Index: runtime/vm/bit_vector.h
===================================================================
--- runtime/vm/bit_vector.h	(revision 23243)
+++ runtime/vm/bit_vector.h	(working copy)
@@ -48,7 +48,6 @@
       : length_(length),
         data_length_(SizeFor(length)),
         data_(Isolate::Current()->current_zone()->Alloc<uword>(data_length_)) {
-    ASSERT(length > 0);

[hausner, 2013/05/28 17:00:47]

Why remove this?

[Florian Schneider, 2013/05/30 09:29:31]

Bitvectors used by liveness analysis can now be of length zero. Before there was
always at least the array_literal_var in each function.

I removed this assert so that I don't need to handle the zero-length case in a
lot of places in the optimizer. The BitVector class works otherwise just fine
with a zero-length.

     Clear();
   }