Add assembler test.

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 7f8486af4ec361a45830351c54f1fd761fd00a46..e0dac29af068356724c13e97fefb92e1ca822694 100644
--- a/src/mips64/macro-assembler-mips64.h
+++ b/src/mips64/macro-assembler-mips64.h
@@ -655,6 +655,12 @@ class MacroAssembler: public Assembler {
 
 #undef DEFINE_INSTRUCTION
 #undef DEFINE_INSTRUCTION2
+#undef DEFINE_INSTRUCTION3
+
+  void Lsa(Register rd, Register rs, Register rt, uint8_t sa,
+           Register scratch = at);
+  void Dlsa(Register rd, Register rs, Register rt, uint8_t sa,
+            Register scratch = at);
 
   void Pref(int32_t hint, const MemOperand& rs);