ART: Clean up utils.h

Remove functionality provided by libbase. Move some single-use
functions to their respective users.

Test: m test-art-host
Change-Id: I75594035fa975200d638cc29bb9f31bc6e6cb29f
diff --git a/compiler/optimizing/instruction_simplifier.cc b/compiler/optimizing/instruction_simplifier.cc
index 658b804..c615df1 100644
--- a/compiler/optimizing/instruction_simplifier.cc
+++ b/compiler/optimizing/instruction_simplifier.cc
@@ -1185,6 +1185,18 @@
   RecordSimplification();
 }
 
+// Return whether x / divisor == x * (1.0f / divisor), for every float x.
+static constexpr bool CanDivideByReciprocalMultiplyFloat(int32_t divisor) {
+  // True, if the most significant bits of divisor are 0.
+  return ((divisor & 0x7fffff) == 0);
+}
+
+// Return whether x / divisor == x * (1.0 / divisor), for every double x.
+static constexpr bool CanDivideByReciprocalMultiplyDouble(int64_t divisor) {
+  // True, if the most significant bits of divisor are 0.
+  return ((divisor & ((UINT64_C(1) << 52) - 1)) == 0);
+}
+
 void InstructionSimplifierVisitor::VisitDiv(HDiv* instruction) {
   HConstant* input_cst = instruction->GetConstantRight();
   HInstruction* input_other = instruction->GetLeastConstantLeft();