X87: Write barrier for storing a code entry, and usage in CompileLazy builtin.

src/x87/code-stubs-x87.h

Index: src/x87/code-stubs-x87.h
diff --git a/src/x87/code-stubs-x87.h b/src/x87/code-stubs-x87.h
index a6a2a1305735b33b78ae9da1c95a22ba8dddfe2c..39a4603626f55301fba1c12c0d5c36f2f791f1ca 100644
--- a/src/x87/code-stubs-x87.h
+++ b/src/x87/code-stubs-x87.h
@@ -271,24 +271,12 @@ class RecordWriteStub: public PlatformCodeStub {
     // registers are eax, ecx and edx.  The three scratch registers (incl. ecx)
     // will be restored by other means so we don't bother pushing them here.
     void SaveCallerSaveRegisters(MacroAssembler* masm, SaveFPRegsMode mode) {
-      if (!scratch0_.is(eax) && !scratch1_.is(eax)) masm->push(eax);
-      if (!scratch0_.is(edx) && !scratch1_.is(edx)) masm->push(edx);
-      if (mode == kSaveFPRegs) {
-        // Save FPU state in m108byte.
-        masm->sub(esp, Immediate(108));
-        masm->fnsave(Operand(esp, 0));
-      }
+      masm->PushCallerSaved(mode, ecx, scratch0_, scratch1_);
     }
 
     inline void RestoreCallerSaveRegisters(MacroAssembler* masm,
                                            SaveFPRegsMode mode) {
-      if (mode == kSaveFPRegs) {
-        // Restore FPU state in m108byte.
-        masm->frstor(Operand(esp, 0));
-        masm->add(esp, Immediate(108));
-      }
-      if (!scratch0_.is(edx) && !scratch1_.is(edx)) masm->pop(edx);
-      if (!scratch0_.is(eax) && !scratch1_.is(eax)) masm->pop(eax);
+      masm->PopCallerSaved(mode, ecx, scratch0_, scratch1_);
     }
 
     inline Register object() { return object_; }