X87: Reland "[turbofan] Discard the shared code entry in the optimized code map.".

  port ec132e05 (r40086)

  original commit message:
  (GcStress failure was unrelated.)

  At one time, we hoped to generate the same code for different
  native contexts. But in truth, much performance comes from optimizing
  on the native context. Now we abandon this pathway.

BUG=

Review-Url: https://codereview.chromium.org/2404843002
Cr-Commit-Position: refs/heads/master@{#40147}

src/builtins/x87/builtins-x87.cc

@@ -1056,7 +1056,6 @@ void Builtins::Generate_CompileLazy(MacroAssembler* masm) {
   // -----------------------------------
   // First lookup code, maybe we don't need to compile!
   Label gotta_call_runtime, gotta_call_runtime_no_stack;
-  Label maybe_call_runtime;
   Label try_shared;
   Label loop_top, loop_bottom;
 
@@ -1119,15 +1118,12 @@ void Builtins::Generate_CompileLazy(MacroAssembler* masm) {
   __ mov(entry, FieldOperand(map, index, times_half_pointer_size,
                              SharedFunctionInfo::kOffsetToPreviousCachedCode));
   __ mov(entry, FieldOperand(entry, WeakCell::kValueOffset));
-  __ JumpIfSmi(entry, &maybe_call_runtime);
+  __ JumpIfSmi(entry, &try_shared);
 
   // Found literals and code. Get them into the closure and return.
   __ pop(closure);
   // Store code entry in the closure.
   __ lea(entry, FieldOperand(entry, Code::kHeaderSize));
-
-  Label install_optimized_code_and_tailcall;
-  __ bind(&install_optimized_code_and_tailcall);
   __ mov(FieldOperand(closure, JSFunction::kCodeEntryOffset), entry);
   __ RecordWriteCodeEntryField(closure, entry, eax);
 
@@ -1161,20 +1157,8 @@ void Builtins::Generate_CompileLazy(MacroAssembler* masm) {
   // We found neither literals nor code.
   __ jmp(&gotta_call_runtime);
 
-  __ bind(&maybe_call_runtime);
-  __ pop(closure);
-
-  // Last possibility. Check the context free optimized code map entry.
-  __ mov(entry, FieldOperand(map, FixedArray::kHeaderSize +
-                                      SharedFunctionInfo::kSharedCodeIndex));
-  __ mov(entry, FieldOperand(entry, WeakCell::kValueOffset));
-  __ JumpIfSmi(entry, &try_shared);
-
-  // Store code entry in the closure.
-  __ lea(entry, FieldOperand(entry, Code::kHeaderSize));
-  __ jmp(&install_optimized_code_and_tailcall);
-
   __ bind(&try_shared);
+  __ pop(closure);
   __ pop(new_target);
   __ pop(argument_count);
   // Is the full code valid?