Refactor RangeBoundary +/- infinity to be distinct RangeBoundary kinds.

runtime/vm/intermediate_language_ia32.cc

Index: runtime/vm/intermediate_language_ia32.cc
diff --git a/runtime/vm/intermediate_language_ia32.cc b/runtime/vm/intermediate_language_ia32.cc
index 83e6f5d6fccf1513b9629bb333927bc15a3bfd31..cf0c972d3d7cca209540a4ace7ea330416918e5e 100644
--- a/runtime/vm/intermediate_language_ia32.cc
+++ b/runtime/vm/intermediate_language_ia32.cc
@@ -2901,8 +2901,7 @@ static void EmitSmiShiftLeft(FlowGraphCompiler* compiler,
   if (is_truncating) {
     if (right_needs_check) {
       const bool right_may_be_negative =
-          (right_range == NULL) ||
-          !right_range->IsWithin(0, RangeBoundary::kPlusInfinity);
+          (right_range == NULL) || !right_range->IsPositive();
       if (right_may_be_negative) {
         ASSERT(shift_left->CanDeoptimize());
         __ cmpl(right, Immediate(0));
@@ -3268,7 +3267,7 @@ void BinarySmiOpInstr::EmitNativeCode(FlowGraphCompiler* compiler) {
         __ jmp(&done, Assembler::kNearJump);
         __ Bind(&subtract);
         __ subl(result, right);
-      } else if (right_range->IsWithin(0, RangeBoundary::kPlusInfinity)) {
+      } else if (right_range->IsPositive()) {
         // Right is positive.
         __ addl(result, right);
       } else {
@@ -3288,7 +3287,7 @@ void BinarySmiOpInstr::EmitNativeCode(FlowGraphCompiler* compiler) {
       // sarl operation masks the count to 5 bits.
       const intptr_t kCountLimit = 0x1F;
       if ((right_range == NULL) ||
-          !right_range->IsWithin(RangeBoundary::kMinusInfinity, kCountLimit)) {
+          !right_range->OnlyLessThanOrEqualTo(kCountLimit)) {
         __ cmpl(right, Immediate(kCountLimit));
         Label count_ok;
         __ j(LESS, &count_ok, Assembler::kNearJump);
@@ -5360,7 +5359,7 @@ void MergedMathInstr::EmitNativeCode(FlowGraphCompiler* compiler) {
       __ jmp(&done, Assembler::kNearJump);
       __ Bind(&subtract);
       __ subl(EDX, right);
-    } else if (right_range->IsWithin(0, RangeBoundary::kPlusInfinity)) {
+    } else if (right_range->IsPositive()) {
       // Right is positive.
       __ addl(EDX, right);
     } else {