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 fbf3ebae1e5c4ae9f9969c4efa86ee38384134da..dcc1ca6e1d3d9d1859c917fb576426019d568247 100644
--- a/runtime/vm/intermediate_language_ia32.cc
+++ b/runtime/vm/intermediate_language_ia32.cc
@@ -2902,8 +2902,7 @@ 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));
@@ -3269,7 +3268,7 @@ 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 {
@@ -3289,7 +3288,7 @@ 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);
@@ -5362,7 +5361,7 @@ 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 {