[builtins] Simplify String constructor code.

src/mips64/macro-assembler-mips64.h

Index: src/mips64/macro-assembler-mips64.h
diff --git a/src/mips64/macro-assembler-mips64.h b/src/mips64/macro-assembler-mips64.h
index f69a68f59e3b4c08d0e69303944701ee2cdd71cc..3d1cbe35f21119323e39574babbb7c7eb9cc5227 100644
--- a/src/mips64/macro-assembler-mips64.h
+++ b/src/mips64/macro-assembler-mips64.h
@@ -254,6 +254,8 @@ class MacroAssembler: public Assembler {
 
   void Call(Label* target);
 
+  void Move(Register dst, Smi* smi) { li(dst, Operand(smi)); }
+
   inline void Move(Register dst, Register src) {
     if (!dst.is(src)) {
       mov(dst, src);
@@ -1595,18 +1597,6 @@ const Operand& rt = Operand(zero_reg), BranchDelaySlot bd = PROTECT
   // -------------------------------------------------------------------------
   // String utilities.
 
-  // Generate code to do a lookup in the number string cache. If the number in
-  // the register object is found in the cache the generated code falls through
-  // with the result in the result register. The object and the result register
-  // can be the same. If the number is not found in the cache the code jumps to
-  // the label not_found with only the content of register object unchanged.
-  void LookupNumberStringCache(Register object,
-                               Register result,
-                               Register scratch1,
-                               Register scratch2,
-                               Register scratch3,
-                               Label* not_found);
-
   // Checks if both instance types are sequential one-byte strings and jumps to
   // label if either is not.
   void JumpIfBothInstanceTypesAreNotSequentialOneByte(