PPC: Move work to omit unnecessary ObjectLiteral stores to the numbering pass.

Port 32de6778

Original commit message:
The reason is that this information will be needed to compute the number of
vector ic slots done at numbering time.

R=mvstanton@chromium.org, dstence@us.ibm.com, michael_dawson@ca.ibm.com
BUG=

Review URL: https://codereview.chromium.org/1153113002

Cr-Commit-Position: refs/heads/master@{#28633}

src/ppc/full-codegen-ppc.cc

@@ -1634,11 +1634,6 @@ void FullCodeGenerator::VisitObjectLiteral(ObjectLiteral* expr) {
   // result_saved is false the result is in r3.
   bool result_saved = false;
 
-  // Mark all computed expressions that are bound to a key that
-  // is shadowed by a later occurrence of the same key. For the
-  // marked expressions, no store code is emitted.
-  expr->CalculateEmitStore(zone());
-
   AccessorTable accessor_table(zone());
   int property_index = 0;
   for (; property_index < expr->properties()->length(); property_index++) {