PPC/s390: Reland "[turbofan] Discard the shared code entry in the optimized code map."

src/builtins/ppc/builtins-ppc.cc

Index: src/builtins/ppc/builtins-ppc.cc
diff --git a/src/builtins/ppc/builtins-ppc.cc b/src/builtins/ppc/builtins-ppc.cc
index 79131c9cc947d590681af8c4451f902a340f026a..019b443a35791025d53a50514530d90dfc0bc3a9 100644
--- a/src/builtins/ppc/builtins-ppc.cc
+++ b/src/builtins/ppc/builtins-ppc.cc
@@ -1398,7 +1398,6 @@ void Builtins::Generate_CompileLazy(MacroAssembler* masm) {
   // -----------------------------------
   // First lookup code, maybe we don't need to compile!
   Label gotta_call_runtime;
-  Label maybe_call_runtime;
   Label try_shared;
   Label loop_top, loop_bottom;
 
@@ -1460,14 +1459,11 @@ void Builtins::Generate_CompileLazy(MacroAssembler* masm) {
            FieldMemOperand(array_pointer,
                            SharedFunctionInfo::kOffsetToPreviousCachedCode));
   __ LoadP(entry, FieldMemOperand(entry, WeakCell::kValueOffset));
-  __ JumpIfSmi(entry, &maybe_call_runtime);
+  __ JumpIfSmi(entry, &try_shared);
 
   // Found literals and code. Get them into the closure and return.
   // Store code entry in the closure.
   __ addi(entry, entry, Operand(Code::kHeaderSize - kHeapObjectTag));
-
-  Label install_optimized_code_and_tailcall;
-  __ bind(&install_optimized_code_and_tailcall);
   __ StoreP(entry, FieldMemOperand(closure, JSFunction::kCodeEntryOffset), r0);
   __ RecordWriteCodeEntryField(closure, entry, r8);
 
@@ -1502,19 +1498,6 @@ void Builtins::Generate_CompileLazy(MacroAssembler* masm) {
   // We found neither literals nor code.
   __ b(&gotta_call_runtime);
 
-  __ bind(&maybe_call_runtime);
-
-  // Last possibility. Check the context free optimized code map entry.
-  __ LoadP(entry,
-           FieldMemOperand(map, FixedArray::kHeaderSize +
-                                    SharedFunctionInfo::kSharedCodeIndex));
-  __ LoadP(entry, FieldMemOperand(entry, WeakCell::kValueOffset));
-  __ JumpIfSmi(entry, &try_shared);
-
-  // Store code entry in the closure.
-  __ addi(entry, entry, Operand(Code::kHeaderSize - kHeapObjectTag));
-  __ b(&install_optimized_code_and_tailcall);
-
   __ bind(&try_shared);
   // Is the full code valid?
   __ LoadP(entry,