Avoid accessing Isolate in source position logging.

src/crankshaft/mips/lithium-codegen-mips.cc

Index: src/crankshaft/mips/lithium-codegen-mips.cc
diff --git a/src/crankshaft/mips/lithium-codegen-mips.cc b/src/crankshaft/mips/lithium-codegen-mips.cc
index 08357d3a76f80dbb5ca1e3d9f989f34f1563a862..070feb570cb626ee19c3ae45fd47eb65ed96eb17 100644
--- a/src/crankshaft/mips/lithium-codegen-mips.cc
+++ b/src/crankshaft/mips/lithium-codegen-mips.cc
@@ -83,9 +83,6 @@ void LCodeGen::FinishCode(Handle<Code> code) {
   DCHECK(is_done());
   code->set_stack_slots(GetTotalFrameSlotCount());
   code->set_safepoint_table_offset(safepoints_.GetCodeOffset());
-  Handle<ByteArray> source_positions =
-      source_position_table_builder_.ToSourcePositionTable();
-  code->set_source_position_table(*source_positions);
   PopulateDeoptimizationData(code);
 }