Revert "Revert "Fuse long and FP compare & condition on ARM64 in Optimizing.""

This reverts commit bed50d2430e02a3d6b94972e8ab4873d7b3b8be0.

Bug: 21120453
Change-Id: I5e4aab2703966d9324ebde25bd8b83056fdb10ed
diff --git a/compiler/optimizing/instruction_simplifier.cc b/compiler/optimizing/instruction_simplifier.cc
index 017b678..04ba4e1 100644
--- a/compiler/optimizing/instruction_simplifier.cc
+++ b/compiler/optimizing/instruction_simplifier.cc
@@ -517,10 +517,10 @@
 void InstructionSimplifierVisitor::VisitCondition(HCondition* condition) {
   // Try to fold an HCompare into this HCondition.
 
-  // This simplification is currently only supported on x86, x86_64 and ARM.
-  // TODO: Implement it for ARM64 and MIPS64.
+  // This simplification is currently supported on x86, x86_64, ARM and ARM64.
+  // TODO: Implement it for MIPS64.
   InstructionSet instruction_set = GetGraph()->GetInstructionSet();
-  if (instruction_set != kX86 && instruction_set != kX86_64 && instruction_set != kThumb2) {
+  if (instruction_set == kMips64) {
     return;
   }