Avoid using RecordWrite with the context (esi, rsi, cp) as...

src/x64/macro-assembler-x64.cc

Index: src/x64/macro-assembler-x64.cc
===================================================================
--- src/x64/macro-assembler-x64.cc	(revision 3745)
+++ src/x64/macro-assembler-x64.cc	(working copy)
@@ -178,6 +178,11 @@
                                  int offset,
                                  Register value,
                                  Register smi_index) {
+  // The compiled code assumes that record write doesn't change the
+  // context register, so we check that none of the clobbered
+  // registers are rsi.
+  ASSERT(!object.is(rsi) && !value.is(rsi) && !smi_index.is(rsi));
+
   // First, check if a remembered set write is even needed. The tests below
   // catch stores of Smis and stores into young gen (which does not have space
   // for the remembered set bits.