S390: Fix storing to below stack to avoid sampler handler corrupting stored value

src/crankshaft/s390/lithium-codegen-s390.cc

 // Copyright 2014 the V8 project authors. All rights reserved.
 //
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "src/crankshaft/s390/lithium-codegen-s390.h"
 
 #include "src/base/bits.h"
 #include "src/code-factory.h"
 #include "src/code-stubs.h"
@@ skipping 5192 matching lines @@
   // smi
   __ bind(&is_smi);
   __ ClampUint8(result_reg, result_reg);
 
   __ bind(&done);
 }
 
 void LCodeGen::DoDoubleBits(LDoubleBits* instr) {
   DoubleRegister value_reg = ToDoubleRegister(instr->value());
   Register result_reg = ToRegister(instr->result());
-  // TODO(joransiu): Use non-memory version.
-  __ stdy(value_reg, MemOperand(sp, -kDoubleSize));
+  __ lgdr(result_reg, value_reg);
   if (instr->hydrogen()->bits() == HDoubleBits::HIGH) {
-    __ LoadlW(result_reg,
-              MemOperand(sp, -kDoubleSize + Register::kExponentOffset));
+    __ srlg(result_reg, result_reg, Operand(32));
   } else {
-    __ LoadlW(result_reg,
-              MemOperand(sp, -kDoubleSize + Register::kMantissaOffset));
+    __ llgfr(result_reg, result_reg);
   }
 }
 
 void LCodeGen::DoConstructDouble(LConstructDouble* instr) {
   Register hi_reg = ToRegister(instr->hi());
   Register lo_reg = ToRegister(instr->lo());
   DoubleRegister result_reg = ToDoubleRegister(instr->result());
-  // TODO(joransiu): Construct with ldgr
   Register scratch = scratch0();
 
   // Combine hi_reg:lo_reg into a single 64-bit register.
   __ sllg(scratch, hi_reg, Operand(32));
   __ lr(scratch, lo_reg);
 
   // Bitwise convert from GPR to FPR
   __ ldgr(result_reg, scratch);
 }
 
@@ skipping 431 matching lines @@
   __ LoadP(result,
            FieldMemOperand(scratch, FixedArray::kHeaderSize - kPointerSize));
   __ bind(deferred->exit());
   __ bind(&done);
 }
 
 #undef __
 
 }  // namespace internal
 }  // namespace v8