Remove kExceptionPending flag from thread and codegen.

Code just checks if exception_ is NULL instead. Compiled code simply
clears the exception_ field for MOVE_EXCEPTION instead of calling a
helper.

Change-Id: Iefaa780f66c327c3d20598bd71d3c14d7a9c8119
diff --git a/src/compiler/codegen/mir_to_lir.cc b/src/compiler/codegen/mir_to_lir.cc
index 1d64661..2bc0f86 100644
--- a/src/compiler/codegen/mir_to_lir.cc
+++ b/src/compiler/codegen/mir_to_lir.cc
@@ -85,6 +85,7 @@
     case Instruction::MOVE_EXCEPTION:
       cg->GenMoveException(cu, rl_dest);
       break;
+
     case Instruction::RETURN_VOID:
       if (((cu->access_flags & kAccConstructor) != 0) &&
           cu->compiler->RequiresConstructorBarrier(Thread::Current(), cu->dex_file,