Add a few Subzero intrinsics (not the atomic ones yet).

Handle:
* mem{cpy,move,set} (without optimizations for known lengths)
* nacl.read.tp
* setjmp, longjmp
* trap

Mostly see if the dispatching/organization is okay.

BUG= https://code.google.com/p/nativeclient/issues/detail?id=3882
R=stichnot@chromium.org

Review URL: https://codereview.chromium.org/321993002
diff --git a/src/IceTargetLowering.h b/src/IceTargetLowering.h
index 7f798a8..dbb9a42 100644
--- a/src/IceTargetLowering.h
+++ b/src/IceTargetLowering.h
@@ -167,6 +167,7 @@
   virtual void lowerCast(const InstCast *Inst) = 0;
   virtual void lowerFcmp(const InstFcmp *Inst) = 0;
   virtual void lowerIcmp(const InstIcmp *Inst) = 0;
+  virtual void lowerIntrinsicCall(const InstIntrinsicCall *Inst) = 0;
   virtual void lowerLoad(const InstLoad *Inst) = 0;
   virtual void lowerPhi(const InstPhi *Inst) = 0;
   virtual void lowerRet(const InstRet *Inst) = 0;