Introduce {FAST,SLOW}_STRING_WRAPPER_ELEMENTS

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

Index: src/crankshaft/ppc/lithium-codegen-ppc.cc
diff --git a/src/crankshaft/ppc/lithium-codegen-ppc.cc b/src/crankshaft/ppc/lithium-codegen-ppc.cc
index 6f8c7dc7beb669f26466a3940572e098bc209015..52d05bddd8057fbcb9582cf9f91c6f9ca0b691d2 100644
--- a/src/crankshaft/ppc/lithium-codegen-ppc.cc
+++ b/src/crankshaft/ppc/lithium-codegen-ppc.cc
@@ -3086,6 +3086,9 @@ void LCodeGen::DoLoadKeyedExternalArray(LLoadKeyed* instr) {
       case DICTIONARY_ELEMENTS:
       case FAST_SLOPPY_ARGUMENTS_ELEMENTS:
       case SLOW_SLOPPY_ARGUMENTS_ELEMENTS:
+      case FAST_STRING_WRAPPER_ELEMENTS:
+      case SLOW_STRING_WRAPPER_ELEMENTS:
+      case NO_ELEMENTS:
         UNREACHABLE();
         break;
     }
@@ -4271,6 +4274,9 @@ void LCodeGen::DoStoreKeyedExternalArray(LStoreKeyed* instr) {
       case DICTIONARY_ELEMENTS:
       case FAST_SLOPPY_ARGUMENTS_ELEMENTS:
       case SLOW_SLOPPY_ARGUMENTS_ELEMENTS:
+      case FAST_STRING_WRAPPER_ELEMENTS:
+      case SLOW_STRING_WRAPPER_ELEMENTS:
+      case NO_ELEMENTS:
         UNREACHABLE();
         break;
     }