S390: [crankshaft] Fragmentation-free allocation folding.

src/crankshaft/s390/lithium-s390.h

Index: src/crankshaft/s390/lithium-s390.h
diff --git a/src/crankshaft/s390/lithium-s390.h b/src/crankshaft/s390/lithium-s390.h
index b6a161411d9154cdd5eef42ea4fa6e82158ce1fe..e0f762b79a3a1466de995a1c40b399a55d8845b8 100644
--- a/src/crankshaft/s390/lithium-s390.h
+++ b/src/crankshaft/s390/lithium-s390.h
@@ -67,6 +67,7 @@ class LCodeGen;
   V(Drop)                                    \
   V(Dummy)                                   \
   V(DummyUse)                                \
+  V(FastAllocate)                            \
   V(FlooringDivByConstI)                     \
   V(FlooringDivByPowerOf2I)                  \
   V(FlooringDivI)                            \
@@ -2165,6 +2166,22 @@ class LAllocate final : public LTemplateInstruction<1, 2, 2> {
   DECLARE_HYDROGEN_ACCESSOR(Allocate)
 };
 
+class LFastAllocate final : public LTemplateInstruction<1, 1, 2> {
+ public:
+  LFastAllocate(LOperand* size, LOperand* temp1, LOperand* temp2) {
+    inputs_[0] = size;
+    temps_[0] = temp1;
+    temps_[1] = temp2;
+  }
+
+  LOperand* size() { return inputs_[0]; }
+  LOperand* temp1() { return temps_[0]; }
+  LOperand* temp2() { return temps_[1]; }
+
+  DECLARE_CONCRETE_INSTRUCTION(FastAllocate, "fast-allocate")
+  DECLARE_HYDROGEN_ACCESSOR(Allocate)
+};
+
 class LTypeof final : public LTemplateInstruction<1, 2, 0> {
  public:
   LTypeof(LOperand* context, LOperand* value) {