MIPS: port Generated code for substring slices in x64 and arm.

src/mips/macro-assembler-mips.cc

Index: src/mips/macro-assembler-mips.cc
diff --git a/src/mips/macro-assembler-mips.cc b/src/mips/macro-assembler-mips.cc
index 45e901bdb91d3eef2c97f9c99dfbd32e2947228d..12a6a8670daeae96c362ef258a84c8cd67c84838 100644
--- a/src/mips/macro-assembler-mips.cc
+++ b/src/mips/macro-assembler-mips.cc
@@ -2815,6 +2815,46 @@ void MacroAssembler::AllocateAsciiConsString(Register result,
 }
 
 
+void MacroAssembler::AllocateTwoByteSlicedString(Register result,
+                                                 Register length,
+                                                 Register scratch1,
+                                                 Register scratch2,
+                                                 Label* gc_required) {
+  AllocateInNewSpace(SlicedString::kSize,
+                     result,
+                     scratch1,
+                     scratch2,
+                     gc_required,
+                     TAG_OBJECT);
+
+  InitializeNewString(result,
+                      length,
+                      Heap::kSlicedStringMapRootIndex,
+                      scratch1,
+                      scratch2);
+}
+
+
+void MacroAssembler::AllocateAsciiSlicedString(Register result,
+                                               Register length,
+                                               Register scratch1,
+                                               Register scratch2,
+                                               Label* gc_required) {
+  AllocateInNewSpace(SlicedString::kSize,
+                     result,
+                     scratch1,
+                     scratch2,
+                     gc_required,
+                     TAG_OBJECT);
+
+  InitializeNewString(result,
+                      length,
+                      Heap::kSlicedAsciiStringMapRootIndex,
+                      scratch1,
+                      scratch2);
+}
+
+
 // Allocates a heap number or jumps to the label if the young space is full and
 // a scavenge is needed.
 void MacroAssembler::AllocateHeapNumber(Register result,