Add integer min/max constants to globals.h

runtime/vm/object_test.cc

Index: runtime/vm/object_test.cc
diff --git a/runtime/vm/object_test.cc b/runtime/vm/object_test.cc
index 587cd5c95020e5d643ae48b62041630c5c0d39d1..33fc39f672a5342732586d78dca8d36ea183e4b6 100644
--- a/runtime/vm/object_test.cc
+++ b/runtime/vm/object_test.cc
@@ -222,11 +222,11 @@ TEST_CASE(Smi) {
   EXPECT(Smi::IsValid(-15));
   // Upper two bits must be either 00 or 11.
 #if defined(ARCH_IS_64_BIT)
-  EXPECT(!Smi::IsValid(0x7FFFFFFFFFFFFFFF));
+  EXPECT(!Smi::IsValid(kMaxInt64));
   EXPECT(Smi::IsValid(0x3FFFFFFFFFFFFFFF));
   EXPECT(Smi::IsValid(0xFFFFFFFFFFFFFFFF));
 #else
-  EXPECT(!Smi::IsValid(0x7FFFFFFF));
+  EXPECT(!Smi::IsValid(kMaxInt32));
   EXPECT(Smi::IsValid(0x3FFFFFFF));
   EXPECT(Smi::IsValid(0xFFFFFFFF));
 #endif