MIPS: Improve array to string conversion.

src/mips/lithium-mips.cc

Index: src/mips/lithium-mips.cc
diff --git a/src/mips/lithium-mips.cc b/src/mips/lithium-mips.cc
index 56dd33d24600e490b60e7bba2bdc27d38295a219..521b38d0cd04a0a57b0d4586699f08327710c2e7 100644
--- a/src/mips/lithium-mips.cc
+++ b/src/mips/lithium-mips.cc
@@ -1531,6 +1531,16 @@ LInstruction* LChunkBuilder::DoDateField(HDateField* instr) {
 }
 
 
+LInstruction* LChunkBuilder::DoSeqStringSetChar(HSeqStringSetChar* instr) {
+  LOperand* string = UseRegister(instr->string());
+  LOperand* index = UseRegister(instr->index());
+  LOperand* value = UseRegister(instr->value());
+  LSeqStringSetChar* result =
+      new(zone()) LSeqStringSetChar(instr->encoding(), string, index, value);
+  return DefineAsRegister(result);
+}
+
+
 LInstruction* LChunkBuilder::DoBoundsCheck(HBoundsCheck* instr) {
   LOperand* value = UseRegisterOrConstantAtStart(instr->index());
   LOperand* length = UseRegister(instr->length());