Reland "[turbofan] Discard the shared code entry in the optimized code map."

src/builtins/arm64/builtins-arm64.cc

Index: src/builtins/arm64/builtins-arm64.cc
diff --git a/src/builtins/arm64/builtins-arm64.cc b/src/builtins/arm64/builtins-arm64.cc
index b815b85b878a6e3e6ead436447f722a94af83bfe..b6f9041bac2bf09c42d386d7d0c7fb16eeef369f 100644
--- a/src/builtins/arm64/builtins-arm64.cc
+++ b/src/builtins/arm64/builtins-arm64.cc
@@ -1381,7 +1381,6 @@ 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;
 
@@ -1439,13 +1438,10 @@ void Builtins::Generate_CompileLazy(MacroAssembler* masm) {
          FieldMemOperand(array_pointer,
                          SharedFunctionInfo::kOffsetToPreviousCachedCode));
   __ Ldr(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.
   __ Add(entry, entry, Operand(Code::kHeaderSize - kHeapObjectTag));
-
-  Label install_optimized_code_and_tailcall;
-  __ Bind(&install_optimized_code_and_tailcall);
   __ Str(entry, FieldMemOperand(closure, JSFunction::kCodeEntryOffset));
   __ RecordWriteCodeEntryField(closure, entry, x5);
 
@@ -1476,18 +1472,6 @@ 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.
-  __ Ldr(entry, FieldMemOperand(map, FixedArray::kHeaderSize +
-                                         SharedFunctionInfo::kSharedCodeIndex));
-  __ Ldr(entry, FieldMemOperand(entry, WeakCell::kValueOffset));
-  __ JumpIfSmi(entry, &try_shared);
-
-  // Store code entry in the closure.
-  __ Add(entry, entry, Operand(Code::kHeaderSize - kHeapObjectTag));
-  __ B(&install_optimized_code_and_tailcall);
-
   __ Bind(&try_shared);
   // Is the full code valid?
   __ Ldr(entry,