Eliminate temporary locals for some expressions

runtime/vm/scopes.h

Index: runtime/vm/scopes.h
===================================================================
--- runtime/vm/scopes.h	(revision 23243)
+++ runtime/vm/scopes.h	(working copy)
@@ -63,8 +63,6 @@
 
   // Assign an index to a local.
   void set_index(int index) {
-    ASSERT(!HasIndex());

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

Why are you removing these asserts? Does your change depend on being able to set
an index on a variable that has already been allocated? That would seem wrong to
me.

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

I'm setting the index of the new dynamically allocated temps in the graph
builder where I track the stack height used for the index calculation. I could
make the graph builder a friend class of LocalVariable to keep the assert for
the existing uses of set_index.

Since the inliner uses a cache of ASTs we may encounter a local variable
multiple times when inlining at two call-sites that call the same function.

I agree this is a little brittle. I think a better solution would be to avoid
re-using the LocalVariable class for my purpose, but that would involve a lot of
changes, so I didn't want to do that in the first step.

The second ASSERT can actually stay. I removed it over-eagerly.

-    ASSERT(index != kUnitializedIndex);
     index_ = index;
   }