[Ignition] Teach CompileLazy about interpreted functions.

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 0f524e656fb552415157c256201fedbb8777cffb..87dfc7d3a6b6305a4d7ec63c05c36e47b5418a7c 100644
--- a/src/builtins/x64/builtins-x64.cc
+++ b/src/builtins/x64/builtins-x64.cc
@@ -1076,14 +1076,14 @@ void Builtins::Generate_CompileLazy(MacroAssembler* masm) {
   __ testb(FieldOperand(entry, SharedFunctionInfo::kMarkedForTierUpByteOffset),
            Immediate(1 << SharedFunctionInfo::kMarkedForTierUpBitWithinByte));
   __ j(not_zero, &gotta_call_runtime);
-  // Is the full code valid?
+
+  // If SFI points to anything other than CompileLazy, install that.
   __ movp(entry, FieldOperand(entry, SharedFunctionInfo::kCodeOffset));
-  __ movl(rbx, FieldOperand(entry, Code::kFlagsOffset));
-  __ andl(rbx, Immediate(Code::KindField::kMask));
-  __ shrl(rbx, Immediate(Code::KindField::kShift));
-  __ cmpl(rbx, Immediate(Code::BUILTIN));
+  __ Move(rbx, masm->CodeObject());
+  __ cmpp(entry, rbx);
   __ j(equal, &gotta_call_runtime);
-  // Yes, install the full code.
+
+  // Install the SFI's code entry.
   __ leap(entry, FieldOperand(entry, Code::kHeaderSize));
   __ movp(FieldOperand(closure, JSFunction::kCodeEntryOffset), entry);
   __ RecordWriteCodeEntryField(closure, entry, r15);