Revert of [turbofan] Discard the shared code entry in the optimized code map.

src/builtins/x64/builtins-x64.cc

Index: src/builtins/x64/builtins-x64.cc
diff --git a/src/builtins/x64/builtins-x64.cc b/src/builtins/x64/builtins-x64.cc
index afd678fa25c353568031d0ef42050bc5de7d3e54..fb1c5982d3360c991fe2e8db5267fef3de6309d4 100644
--- a/src/builtins/x64/builtins-x64.cc
+++ b/src/builtins/x64/builtins-x64.cc
@@ -1031,6 +1031,7 @@
   // -----------------------------------
   // 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;
 
@@ -1084,10 +1085,13 @@
   __ movp(entry, FieldOperand(map, index, times_pointer_size,
                               SharedFunctionInfo::kOffsetToPreviousCachedCode));
   __ movp(entry, FieldOperand(entry, WeakCell::kValueOffset));
-  __ JumpIfSmi(entry, &try_shared);
+  __ JumpIfSmi(entry, &maybe_call_runtime);
 
   // Found literals and code. Get them into the closure and return.
   __ leap(entry, FieldOperand(entry, Code::kHeaderSize));
+
+  Label install_optimized_code_and_tailcall;
+  __ bind(&install_optimized_code_and_tailcall);
   __ movp(FieldOperand(closure, JSFunction::kCodeEntryOffset), entry);
   __ RecordWriteCodeEntryField(closure, entry, r15);
 
@@ -1119,6 +1123,18 @@
 
   // We found neither literals nor code.
   __ jmp(&gotta_call_runtime);
+
+  __ bind(&maybe_call_runtime);
+
+  // Last possibility. Check the context free optimized code map entry.
+  __ movp(entry, FieldOperand(map, FixedArray::kHeaderSize +
+                                       SharedFunctionInfo::kSharedCodeIndex));
+  __ movp(entry, FieldOperand(entry, WeakCell::kValueOffset));
+  __ JumpIfSmi(entry, &try_shared);
+
+  // Store code entry in the closure.
+  __ leap(entry, FieldOperand(entry, Code::kHeaderSize));
+  __ jmp(&install_optimized_code_and_tailcall);
 
   __ bind(&try_shared);
   // Is the full code valid?