MIPS: Use PCNT to implement VisitIntegerBitCount() and VisitLongBitCount()

Test: ./testrunner.py --target --optimizing in QEMU
Test: mma test-art-host-gtest
Change-Id: I6ce5bdc86f951094f656c2f81ae8fc836d7a0b5c
diff --git a/compiler/optimizing/intrinsics_mips.h b/compiler/optimizing/intrinsics_mips.h
index 13397f1..1c1ba40 100644
--- a/compiler/optimizing/intrinsics_mips.h
+++ b/compiler/optimizing/intrinsics_mips.h
@@ -71,6 +71,7 @@
   bool IsR2OrNewer() const;
   bool IsR6() const;
   bool Is32BitFPU() const;
+  bool HasMsa() const;
 
  private:
   MipsAssembler* GetAssembler();