Fix issue 20190: Mark Uint32/Int32 typed data load to produce a Mint always

runtime/vm/intermediate_language_ia32.cc

Index: runtime/vm/intermediate_language_ia32.cc
===================================================================
--- runtime/vm/intermediate_language_ia32.cc	(revision 38576)
+++ runtime/vm/intermediate_language_ia32.cc	(working copy)
@@ -993,8 +993,8 @@
       // Result can be Smi or Mint when boxed.
       // Instruction can deoptimize if we optimistically assumed that the result
       // fits into Smi.
-      return CanDeoptimize() ? CompileType::FromCid(kSmiCid)
-                             : CompileType::Int();
+      return Typed32BitIsSmi() ? CompileType::FromCid(kSmiCid)
+                               : CompileType::FromCid(kMintCid);
 
     default:
       UNIMPLEMENTED();
@@ -1003,6 +1003,10 @@
 }
 
 
+// TODO(srdjan): Implement this as a flag so that it can be optimized.
+bool  LoadIndexedInstr::Typed32BitIsSmi() const { return false; }
+
+
 Representation LoadIndexedInstr::representation() const {
   switch (class_id_) {
     case kArrayCid:
@@ -1019,9 +1023,7 @@
       return kTagged;
     case kTypedDataInt32ArrayCid:
     case kTypedDataUint32ArrayCid:
-      // Instruction can deoptimize if we optimistically assumed that the result
-      // fits into Smi.
-      return CanDeoptimize() ? kTagged : kUnboxedMint;
+      return Typed32BitIsSmi() ? kTagged : kUnboxedMint;
     case kTypedDataFloat32ArrayCid:
     case kTypedDataFloat64ArrayCid:
       return kUnboxedDouble;