VM: Share object pool entries for optimized static calls.

runtime/vm/assembler_arm64.h

Index: runtime/vm/assembler_arm64.h
diff --git a/runtime/vm/assembler_arm64.h b/runtime/vm/assembler_arm64.h
index ffb6b768f42c28217fbb8d3351d800d2b678abe0..ff159d6566df04f2277b98cb889e9cde98735f09 100644
--- a/runtime/vm/assembler_arm64.h
+++ b/runtime/vm/assembler_arm64.h
@@ -1213,6 +1213,11 @@ class Assembler : public ValueObject {
 
   void BranchLinkPatchable(const StubEntry& stub_entry);
 
+  // Emit a call that shares its object pool entries with other calls
+  // that have the same equivalence marker.
+  void BranchLinkWithEquivalence(const StubEntry& stub_entry,
+                                 const Object& equivalence);
+
   // Macros accepting a pp Register argument may attempt to load values from
   // the object pool when possible. Unless you are sure that the untagged object
   // pool pointer is in another register, or that it is not available at all,