VM: Array bounds checks that don't deoptimize for precompiled code.

runtime/vm/intermediate_language.h

Index: runtime/vm/intermediate_language.h
diff --git a/runtime/vm/intermediate_language.h b/runtime/vm/intermediate_language.h
index 7307344385661d950e42e516f05ba5c558cf60b5..bfcb8a767726f7262ab23fc717f2cc414d8a554f 100644
--- a/runtime/vm/intermediate_language.h
+++ b/runtime/vm/intermediate_language.h
@@ -512,6 +512,7 @@ class EmbeddedArray<T, 0> {
   M(ShiftMintOp)                                                               \
   M(UnaryMintOp)                                                               \
   M(CheckArrayBound)                                                           \
+  M(GenericCheckBound)                                                         \
   M(Constraint)                                                                \
   M(StringToCharCode)                                                          \
   M(OneByteStringFromCharCode)                                                 \
@@ -7928,6 +7929,35 @@ class CheckArrayBoundInstr : public TemplateInstruction<2, NoThrow, Pure> {
 };
 
 
+class GenericCheckBoundInstr : public TemplateInstruction<2, Throws, NoCSE> {
+ public:
+  GenericCheckBoundInstr(Value* length, Value* index, intptr_t deopt_id)
+      : TemplateInstruction(deopt_id) {
+    SetInputAt(kLengthPos, length);
+    SetInputAt(kIndexPos, index);
+  }
+
+  Value* length() const { return inputs_[kLengthPos]; }
+  Value* index() const { return inputs_[kIndexPos]; }
+
+  virtual EffectSet Effects() const { return EffectSet::None(); }
+  virtual EffectSet Dependencies() const { return EffectSet::None(); }
+
+  DECLARE_INSTRUCTION(GenericCheckBound)
+
+  virtual bool CanDeoptimize() const { return true; }
+
+  // Give a name to the location/input indices.
+  enum {
+    kLengthPos = 0,
+    kIndexPos = 1
+  };
+
+ private:
+  DISALLOW_COPY_AND_ASSIGN(GenericCheckBoundInstr);
+};
+
+
 class UnboxedIntConverterInstr : public TemplateDefinition<1, NoThrow> {
  public:
   UnboxedIntConverterInstr(Representation from,