[vm/compiler] Fine tune operator and phi handling.

Rationale:
Running an extra call specialization pass a bit later
in the compiler passes stream (after types are propagated)
recognizes more operators, which execute more efficiently.
In addition, unboxing phis seems useful on all archs, not
just 32-bit. These minor tweeks combined improve the prime
number benchmark 3 fold.

flutter/flutter#19677

Change-Id: Ib2102ce807c2f0a9f801542e0c4bc6a7673f552b
Reviewed-on: https://dart-review.googlesource.com/69240
Reviewed-by: Vyacheslav Egorov <[email protected]>
Commit-Queue: Aart Bik <[email protected]>

Author: aartbik

runtime/vm/compiler/backend/flow_graph.cc

@@ -1730,9 +1730,9 @@ static void UnboxPhi(PhiInstr* phi) {
       break;
   }
 
-  if ((kSmiBits < 32) && (unboxed == kTagged) && phi->Type()->IsInt() &&
+  if ((unboxed == kTagged) && phi->Type()->IsInt() &&
       RangeUtils::Fits(phi->range(), RangeBoundary::kRangeBoundaryInt64)) {
-    // On 32-bit platforms conservatively unbox phis that:
+    // Conservatively unbox phis that:
     //   - are proven to be of type Int;
     //   - fit into 64bits range;
     //   - have either constants or Box() operations as inputs;

runtime/vm/compiler/compiler_pass.cc

@@ -223,6 +223,7 @@ void CompilerPass::RunPipeline(PipelineMode mode,
   INVOKE_PASS(TypePropagation);
   INVOKE_PASS(ApplyClassIds);
   INVOKE_PASS(TypePropagation);
+  INVOKE_PASS(ApplyICData);
   INVOKE_PASS(Canonicalize);
   INVOKE_PASS(BranchSimplify);
   INVOKE_PASS(IfConvert);