Revert^4 "Compiler changes for bitstring based type checks."

Disabled the build time flag. (No image version bump needed.)

Bug: 26687569
Bug: 64692057
Bug: 76420366

This reverts commit 3fbd3ad99fad077e5c760e7238bcd55b07d4c06e.

Change-Id: I5d83c4ce8a7331c435d5155ac6e0ce1c77d60004
diff --git a/compiler/optimizing/code_generator_x86_64.h b/compiler/optimizing/code_generator_x86_64.h
index e8d1efe..9a4c53b 100644
--- a/compiler/optimizing/code_generator_x86_64.h
+++ b/compiler/optimizing/code_generator_x86_64.h
@@ -208,6 +208,7 @@
   // the suspend call.
   void GenerateSuspendCheck(HSuspendCheck* instruction, HBasicBlock* successor);
   void GenerateClassInitializationCheck(SlowPathCode* slow_path, CpuRegister class_reg);
+  void GenerateBitstringTypeCheckCompare(HTypeCheckInstruction* check, CpuRegister temp);
   void HandleBitwiseOperation(HBinaryOperation* operation);
   void GenerateRemFP(HRem* rem);
   void DivRemOneOrMinusOne(HBinaryOperation* instruction);