S390: [crankshaft] Fragmentation-free allocation folding.

src/s390/macro-assembler-s390.h

Index: src/s390/macro-assembler-s390.h
diff --git a/src/s390/macro-assembler-s390.h b/src/s390/macro-assembler-s390.h
index 8f8194415ea837ef2732960b2a820836d60b3abf..5b65178b446abfd581fff99a25c1269585b94cbc 100644
--- a/src/s390/macro-assembler-s390.h
+++ b/src/s390/macro-assembler-s390.h
@@ -965,6 +965,15 @@ class MacroAssembler : public Assembler {
   void Allocate(Register object_size, Register result, Register result_end,
                 Register scratch, Label* gc_required, AllocationFlags flags);
 
+  // FastAllocate is right now only used for folded allocations. It just
+  // increments the top pointer without checking against limit. This can only
+  // be done if it was proved earlier that the allocation will succeed.
+  void FastAllocate(int object_size, Register result, Register scratch1,
+                    Register scratch2, AllocationFlags flags);
+
+  void FastAllocate(Register object_size, Register result, Register result_end,
+                    Register scratch, AllocationFlags flags);
+
   void AllocateTwoByteString(Register result, Register length,
                              Register scratch1, Register scratch2,
                              Register scratch3, Label* gc_required);