Reland "Fix stepping in for-loops."

src/mips64/full-codegen-mips64.cc

Index: src/mips64/full-codegen-mips64.cc
diff --git a/src/mips64/full-codegen-mips64.cc b/src/mips64/full-codegen-mips64.cc
index 06c3bb45b5c400d7a72a118a69632833e8e21e31..4fb5629af34a8b98ac7ea44fa5a0305423c0ed0d 100644
--- a/src/mips64/full-codegen-mips64.cc
+++ b/src/mips64/full-codegen-mips64.cc
@@ -1097,6 +1097,7 @@ void FullCodeGenerator::VisitForInStatement(ForInStatement* stmt) {
 
   // Get the object to enumerate over. If the object is null or undefined, skip
   // over the loop.  See ECMA-262 version 5, section 12.6.4.
+  SetExpressionPosition(stmt->enumerable());
   VisitForAccumulatorValue(stmt->enumerable());
   __ mov(a0, result_register());  // Result as param to InvokeBuiltin below.
   __ LoadRoot(at, Heap::kUndefinedValueRootIndex);
@@ -1196,6 +1197,8 @@ void FullCodeGenerator::VisitForInStatement(ForInStatement* stmt) {
   // Generate code for doing the condition check.
   PrepareForBailoutForId(stmt->BodyId(), NO_REGISTERS);
   __ bind(&loop);
+  SetExpressionPosition(stmt->each());
+
   // Load the current count to a0, load the length to a1.
   __ ld(a0, MemOperand(sp, 0 * kPointerSize));
   __ ld(a1, MemOperand(sp, 1 * kPointerSize));
@@ -1265,48 +1268,6 @@ void FullCodeGenerator::VisitForInStatement(ForInStatement* stmt) {
 }
 
 
-void FullCodeGenerator::VisitForOfStatement(ForOfStatement* stmt) {
-  Comment cmnt(masm_, "[ ForOfStatement");
-  SetStatementPosition(stmt);
-
-  Iteration loop_statement(this, stmt);
-  increment_loop_depth();
-
-  // var iterator = iterable[Symbol.iterator]();
-  VisitForEffect(stmt->assign_iterator());
-
-  // Loop entry.
-  __ bind(loop_statement.continue_label());
-
-  // result = iterator.next()
-  VisitForEffect(stmt->next_result());
-
-  // if (result.done) break;
-  Label result_not_done;
-  VisitForControl(stmt->result_done(),
-                  loop_statement.break_label(),
-                  &result_not_done,
-                  &result_not_done);
-  __ bind(&result_not_done);
-
-  // each = result.value
-  VisitForEffect(stmt->assign_each());
-
-  // Generate code for the body of the loop.
-  Visit(stmt->body());
-
-  // Check stack before looping.
-  PrepareForBailoutForId(stmt->BackEdgeId(), NO_REGISTERS);
-  EmitBackEdgeBookkeeping(stmt, loop_statement.continue_label());
-  __ jmp(loop_statement.continue_label());
-
-  // Exit and decrement the loop depth.
-  PrepareForBailoutForId(stmt->ExitId(), NO_REGISTERS);
-  __ bind(loop_statement.break_label());
-  decrement_loop_depth();
-}
-
-
 void FullCodeGenerator::EmitNewClosure(Handle<SharedFunctionInfo> info,
                                        bool pretenure) {
   // Use the fast case closure allocation code that allocates in new